Antivirus
by Azure Reprise
Summary: Gaster has made a habit of watching the timelines from the safety of his gray room. Observing. But now, something has happened to the timelines. Something new. Something very, very... Interesting.
1. VOID

It is a little known or acknowledged fact that for every alternate timeline, there is in fact, an alternate W.D. Gaster that inhabits that timeline. Or rather, inhabited. However, Gasters in the Void cannot perceive each other, only Gasters that were not erased in their respective timelines. One major reason for this is the gray rooms. The gray rooms are where most Gasters are found. They are pockets of existence latched onto the timelines of the Gasters that inhabit them, but not directly inside the timelines and therefor not viewable by the other Gasters.

Every Gaster in the Void, such as the partially melted one currently peering intently at the back wall of his gray room, is able to perceive and view timelines, seeing as the Void was the space between them. In the words of this Gaster, it was almost like watching TV.

TV where you got to watch your friends and loved ones toyed with and/or murdered by either a benign or malevolent, space-time controlling anomaly.

But that was not what Gaster was looking at. He had pushed away from those 'shows' long ago. They were all extremely similar, regardless. No, what Gaster was looking at was something much, much different. It was a timeline the scientist couldn't access.

Ordinarily, he merely had to prod at one of the arching white lines on the wall to view what happened or was happening in that timeline, and the 'current' timeline was always outlined in red; presumably to symbolize the determination of the human within.

This time, however, the current timeline's vibrant red outline seemed to be washed out, with the primary white now an odd pinkish color. That alone was unsettling enough, as the only other time a timeline changed color was when the fallen child annihilated it, turning the line from bright white to pitch black.

Even so, there were two things that made this situation even more alarming. Firstly, the pink was starting to bleed past the red borders. Second, the timeline was starting to fracture, its ends splintering off. Now, this would be fascinating to the scientist if not for one thing: the splintering had already touched two other timelines, and it was gradually turning them pink. These changed timelines were getting unstable, and the scientist hypothesized that they would collapse entirely if not treated.

This was a virus.

Gaster's lone functioning, albeit lightless, eyesocket quickly took this information in, the ex-Royal Scientist's mind working to try to find a solution. Brilliant though he may be, Gaster could only find one solution: Walk into the timeline, and manually destroy the anomaly before its virus corrupted, fractured, and collapsed every other timeline. He had to contain this infection.

Gaster sighed. Just had to be only one way for everything, didn't it? Fine. He reached into his less-melted sleeve and pulled out his last resort. It wasn't very impressive, to say the least. A little tube, metal cap melted and fused to the glass, and sloshing with a thick, red liquid. A vial of Determination. Gaster sighed again. He had been saving this in case he ever found a way to return to his own timeline. To exist again. He wanted to see if any Alphys found a way to safely bring their Gaster back, or, failing that, if they found a way to safely inject DT into a monster.

But this was the fate of every timeline on the line here. He had to do it, no matter the risk. Besides, he already knew that door, which he had mainly just placed there to act as his hope for returning, occasionally appeared in Waterfall. That's how Frisk found him, after all. A Frisk, anyways. He was certain with enough Determination, that he could make it work.

Well, he wasn't certain. Not at all. But he had to at least _try_. Besides, he was partially melted already, what could a bit more do?

"❄ ✋💧 ✡ ❄✋ 📬" _{There is only one option.}_

"✋ ✌✞ 👍 ✋👍 📬" _{I have no choice.}_

"📬📬📬 ✋ ✌💣 👎 ❄ 💣✋ 👎" _{… I am_ _ **Determined**_ _.}_

With that, Gaster broke the cap off the vial, and gulped down the liquid. The effect was immediate. His entire body felt like it was being ripped apart, atom by atom. _Again_. He started to melt even further as his non-melted eye socket gained a blazing red iris. He had no time to lose.

Gaster slammed a skeletal fist into the fractured timeline, pumping his magic into it, then through his body into the door. AS soon as he felt the connection form, he squeezed his sockets shut and bolted for the door, throwing it open and diving through. 

* * *

**LV - -**

 **HP - -/- -**

 **File created.**


	2. RUINS

The first thing Gaster noticed, was that he felt whole. It had been, he assumed, years since he had this feeling, and it was almost overwhelming. Granted he still had the cracks in his skull, and the holes in his hands, but he was _whole_ and _not melted_. That in and of itself was an amazing and wonderful feeling for him.

The second thing he noticed, was the distinct sound of air rushing past him. _Odd,_ He thought. _There usually isn't this much wind in this part of Waterfall._

And then he opened his eye sockets.

What greeted him was distinctly _not_ Waterfall.

It was, instead, a bed of buttercups approximately eighty feet below him and approaching fast.

Now, Gaster is a man of intellect. A man with a PhD. A man who has done great things for monster kind.

"✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌✌📫📫"

And a man who was screaming his skull off until he hit the flowerbed. Gaster, at this specific point in time, did not care in the slightest about how he looked based on his reputation. He did, however, care that he was face down, and had a job to do. He also cared about the distinct ache he had everywhere on his body.

"👎✌💣 ✋❄📬" _{Damn it.}_

Despite that, the scientist slowly rose to his feet and did a quick check. Body no longer melted, black clothes and labcoat with white turtleneck in good condition, eyelights functioning, magic ready. Though, to be safe, he did a short test.

He threw his left arm out. Bones spiked up from the ground to reach the far wall of the cavern. He threw his right arm out. A blaster materialized and fired. He raised both hands. A magic copy of them floated in front of him.

Gaster couldn't help but crack a smile, this wouldn't be too bad. "Hm. Everything in working order… Even my voice seems to allow for normal speech," he said, finishing up his mental checklist before his smile turned giddy. "I can be understood again! I exist again!" He practically cheered before remembering that he had a job to do.

Gaster promptly cleared his nonexistent throat, and strode through the door into the Ruins proper, as he had seen the human do time and time again. 

* * *

_No flower…_ He thought to himself as he walked past Flowey's usual spot in that illuminated entrance area. The scientist pitied Asriel, he truly did, but he could not let the young prince's new form get in his way. Flowey had a reputation for causing trouble, given his distorted worldview, and Gaster could not allow the soulless vessel to stop him.

However, the lack of Flowey meant that the viral anomaly had already made it past here, and possibly the Ruins as a whole. Given the other timelines, this meant that everything here was either dead, corrupted, or both. Not very reassuring for the scientist that now had to venture through the area.

Of course, that only meant he had to move faster. He couldn't let it complete this 'Run' or this timeline would be locked into place. Unchangeable to all but those with the power to SAVE and LOAD. He couldn't let that happen. He _refused_ to let that happen. He was _Determined_ to stop it from happening. 

* * *

The puzzles were trivial for a man of Gaster's intellect. Well, that and he'd seen the human solve them dozens of times, of course. He had them practically memorized by now. Even if they were a challenge, the Queen always was a merciful sort. These puzzles had no bite to them at all. No punishment for failure short of a small detour. At worst, it was just a minor waste of time.

On the bright side, he had seen some monsters around. Mostly Froggits and Whimsuns, but monsters nonetheless. That meant that genocide was out of the question, which was always a good thing. In fact, there didn't seem to be even a single speck of monster dust around the purple halls, which was amazing. Unfortunately, it made what he had to do in the end even harder. That meant that this anomaly was not one for wanton murder. Even if they were inadvertently annihilating entire timelines with their viral presence in this one. At least they would have low HP. He could make it quick.

As he walked past monsters, he used an old trick of his. One he had taught Sans. His eyelights glowed brightly, casting a piercing gaze right into the souls of the monsters he saw. And what he saw only made him more worried. Every single one of their souls was practically glowing with that same pinkish tint that covered the timeline when he had viewed it in his gray room. It had been through here, that much was obvious.

After an annoyingly long and oddly tense hallway, Gaster found a lone Froggit sitting by the doorway, the room's floor decorated with patches of reddened leaves. Seemed good enough for conversation. To at least see if anything… bad had happened. So Gaster, tall as he was, knelt down on one knee to get to the proper height and asked, "Hello, have you perhaps seen a human come by here?"

"Ribbit, ribbit. (Oh yes, a human did come by. Older than the usual children, and a great listener! I have no doubt she'll do great things.)" It said with confidence, the pink glow pulsing with its words.

 _Unnerving._ was the first thought to come to Gaster's mind at noticing that detail. Regardless, he thanked the small monster and stood. There was no time to waste, he had to get moving _now_ , lest the virus reach the Queen. He could not let Toriel fall.

So Gaster turned and took a step forward, only to bump into something fuzzy, about his height, and fall backwards on his rear.

"Oh my, are you alright?" The kindly voice came, before Toriel gasped, recognition gleaming in her eyes as all her memories of the skeleton man before her were instantaneously restored. "... Doctor Gaster?"

Said skeleton rubbed at his skull, before his eyesockets opened up, letting him see the concerned Queen of Monsters standing over him. "Ah, yes, your Highness?" He asked more out of old habits that he had when he still existed than out of acknowledgement of her title. She had left the throne, anyways, hadn't she?

That was unimportant. Gaster got to his feet, idly dusting himself off. He hadn't quite realized, but Toriel had been asking him a stream of questions, and had taken hold of his hand.

Toriel, despite her size, was a rather fast monster, which Gaster got to see firsthand as she held his hand and rushed through the Ruins, motherly instincts in full swing. Well, he'd seen enough timelines to know where this was going.

And he wasn't about to complain about free pie. The queen made the best, and he hadn't actually eaten in…

It was hard to keep track of time in the Void.

That didn't matter. Though some other monsters were making a path for her as she passed, dragging him behind her. Perhaps the old customs still fit, and they were respectful enough to clear a path for the queen? Truth be told, he had mainly focused on the human when he viewed timelines.

Or… them.

 _No. Now is not the time to get sentimental._ He told himself, shaking his head. _Work to be done. Can't get sidetracked._ He repeated this in his head, over and over, as Toriel dragged him right up to her tidy little home in the Ruins. He was making it through the Underground, quite like the human usually did. He had to suppress a shudder at that. I will not be like them.

Oddly enough, as they went inside, he could have sworn he saw a golden gleam in the corner of his vision, on a patch of leaves by the entrance.

Must've just been his imagination. 

* * *

As soon as he was inside, he was plopped right down at the table as the Boss Monster rushed into the kitchen. "Your majesty, this really isn't necessary," He said, starting to stand.

Toriel leaned a bit out of the doorway, smiling wide. "Nonsense! Consider it a 'Welcome Home' present!" She said, before giggling at the half joke she made. _Unusual. Her jokes are usually of a higher caliber than that. Though not by much._ He thought to himself with a grimace, before smiling back at her.

"Ah! Excellent! This will only take a moment!" She said, in an almost sing-song voice before retreating back into the kitchen fully. _Oddly enthusiastic for a woman of her age, too._ He mentally noted, trying to go over the facts that he had. Thus began Gaster's deep thought process. The workings of the greatest mind in the underground were a mystery

This viral anomaly was at least through the Ruins.

Seemingly every monster it had interacted with exhibited behavioral changes, as well as a pinkish aura around the soul.

Therefore, every monster that came into direct contact with the anomaly was "infected" by it.

"Infected" monsters, theoretically, reinforce the "infection."

Thus, the anomaly is a virus.

The virus, hypothetically, affects "major encounters" such as Queen Toriel and… Papyrus, for example, in a stronger way than it affects "lesser encounters" such as the Froggit he had spoken with.

He was fairly certain he classed as a "major encounter."

Therefore, he should always avoid direct contact with the virus.

The doctor smiled. Well, he had his precautions down! Now, how to deal with this virus without getting close? And then, Gaster zoned right back out. 

* * *

"Doctor Gaster?" Toriel asked, gently shaking the scientist's shoulder. His eyelights had gone out and he was staring intently at the far wall. The goat woman was starting to get worried, as he'd been up to this for about half an hour. Straight.

Gaster jumped, eyelights flickering back to life as he looked around. "Oh! Did I, ah, space out again? I'm terribly sorry, your majesty." He said, nodding quickly. Toriel merely chuckled and put a hand on his shoulder blade, lightly pushing him back into his seat.

"Oh it is no trouble! Though I thought I should tell you, the pie is ready," She said, setting the plate she had been carrying down on the table in front of him. Butterscotch-Cinnamon. If he remembered correctly, this was a rarity from her.

So naturally Doctor Gaster wolfed it down. It was probably one of the best things he had ever tasted.

On finishing his plate, Toriel smiled and took it, headed towards the kitchen. "My my, you were hungry! I'll get you another slice." Gaster couldn't help but smile, standing. "Oh, your majesty, there is no need, that was delicious, thank you. However, I must be leaving. I have been gone for quite some time, and I need to get everything in order, now that I've returned."

"Oh of course! Well, know that you are welcome back any time. But, I have a… difficult request of you. Please, do not tell anyone I am here. I stepped down from the throne, you see," She said slowly, to which the skeleton nodded. "Of course, your majesty. I will respect your wishes," He said simply. After all, Gaster knew exactly why she had left the throne. "Though, before I leave, I do have to ask something of you."

"Yes? What is it?" Toriel asked, her smile still wide from his agreeing to keep her location secret. Gaster smiled wide.

"May I borrow that old training dummy you have?"


	3. SNOWDIN

"Say hello to Laura for me!" Toriel called out with a smile as Gaster walked down the long purple hallway.

 _Laura? Wasn't the human Frisk?_ Gaster thought, pulling the collar of his turtleneck up over his mouth and nasal passage. He couldn't have Alphys' cameras catching him, he'd be with the human in an instant. But of course, that would also mean confronting… _them_. 

* * *

It had been years ago that it had happened. Well, he presumed it had been years, anyway. He was the Royal Scientist for King Asgore, working diligently in the labs in Hotland. And one day, he received a letter from the King himself.

Now, Asgore didn't usually get involved with science. He was a sweet guy, but he knew nothing at all about science. That's why "Royal Scientist" was even a position. In a way, it was almost sad. Regardless, Gaster opened the letter immediately, and the contents nearly made him faint.

He was being allowed to research the four human souls they had gathered to attempt to create synthetic souls.

Gaster had very recently finished the CORE and was looking for a new project, but this? This was almost unreal.

As soon as he could, he took up examining the souls, trying to make them work. Trying to duplicate their energy. To do something that would give him a result.  
And then, he did it.  
At long last, he found the key component that separated them. Within days he had two samples ready and growing in their vats, WDG S-1 and WDG P-2. He'd even been in such a hurry that he used DNA samples from himself. Though, as they matured, he realized that while he had injected them with that odd red substance he collected from the souls, he hadn't injected them with nearly enough. That, combined with the fact that his was monster, and not human DNA, resulted in them growing into monsters' souls instead.

He couldn't just kill them, of course not, that would be awful. So he kept and raised them, as if they were his own.

Explaining them to Asgore, however, was an entirely different matter. He had ended up keeping them for quite some time before mustering up the courage to inform the king. Thankfully, Gaster and Asgore had a good bit of history together, which helped smooth the revelation over a bit.

Then he fell into the CORE… 

* * *

He shook his head, blinking as he realized he had been standing in front of the last door out of the ruins for far too long. It was time to get going. He couldn't put this off forever.

He took a deep breath, pushing his hand into his pocket and adjusting his hold on the ghostless dummy under his arm. And then, his magic hands pushed the heavy stone doors open for him.

The snow was almost blinding compared to the dark of the ruins, and Gaster wasn't too proud to admit the slam of the doors shutting behind him startled him. In the end, it didn't matter. He made sure he was facing away from the camera Alphys had in the bushes before he started walking. Now, he could always teleport there, but given how many variables these timelines had, he'd rather not risk it.

He nearly tripped, however, on a heavy-looking branch that was in his path. _Odd, Sans should've broken that by now._ Gaster thought, walking forward.

And then the unmistakable sound of a heavy branch snapping in half echoed behind him.

Gaster was also not too proud to admit that he broke into a dead sprint.

He knew what this was, the dark, snowy forest rushing past in a blur. He knew who had set this up. That didn't mean Gaster was quite prepared to meet him.

When he reached the bridge, he could feel magic start to weigh him down, holding him in place before he crossed it, coupled with the slow, crunching footsteps behind him. The tall skeleton broke into a cold sweat.

" **Don't you know how to greet a new pal?** " The familiar voice sounded behind him, and without thinking, Gaster spun and shook the offered hand.

No noise came.

"what the…?" Sans started, looking down only to see the whoopee cushion still in his hand. It was just going through the hole in the stranger's hand.

Immediately, his eyelights shrank to pinpricks in his sockets, and he looked up at who was shaking his hand.

Just in time to see a magic hand pull down that collar to show his head was a skull.  
Sans would've collapsed if Gaster wasn't still holding him. "dad…? dad is that actually you?"

" _Snow_ body but." Gaster responded with a wink, having used Sans' moment of confusion to compose himself.

There was a tense moment, before they both shared a hearty laugh. For the first time since either of them could remember.  
"dad, you're actually back! i, uh, thought you'd be stuck out there forever, _tibia_ honest." Sans said, rubbing the back of his skull. Gaster simply chuckled, patting Sans' back. "Oh, a few times I did too. But that's not important. There's a lot to discuss! Now, we should probably get to your home before Papyrus shows up…"  
Sans just chuckled. "i know a shortcut." 

* * *

The shortcut let out right in front of the decorated, multilevel home in the sleepy, snow-dusted town. Thus, Gaster took a moment to enjoy the peace. He had a sinking feeling it wouldn't last.

Once inside the skeletons' house, Gaster sat down, took a breath, and explained roughly everything that didn't have to do with the virus, including that he was technically not their father, but one from another timeline. He needed true answer to one specific question before dropping the "virus" bombshell.

And he so dreaded what that answer might be.

"that's a story there, g, but maybe we should tone it down for pap, yeah?" Sans said with a bit of a chuckle, setting the ketchup bottle he had drained in the course of the story down. "Oh, of course! I'm guessing you told your brother something like I was on vacation?"

"actually–"

"SANS, WHO IS THIS?" A very loud voice came from the doorway. Both skeletons turned as one to face the "armored" skeleton in the doorway. "uh, bro, this is… Gaster. y'know, dad." Papyrus took a moment to process this, causing both other skeletons to break out sweating.

And then he lunged forward, hug-tackling Gaster nearly to the floor. "DADDY!"

"It's good to see you, Papyrus." Gaster said between gasps for breath. And skeletons didn't even need to breathe. "DADDY YOU'VE MISSED SO MUCH! I'M IN THE ROYAL GUARD, I'VE GOT LOTS OF PUZZLES, I'M GONNA CAPTURE A HUMAN, I WENT ON A DATE, AND I'M GONNA BE A MASTER CHEF!"

Finally, he let go, meaning he dropped Gaster to the floor, and gasped. Loudly. "NOW THAT YOU'RE BACK, I CAN SERVE YOU SOME OF MY AMAZING SPAGHETTI!" He shouted, somehow louder than usual, before rushing off to the kitchen. Sans just chuckled, helping the scientist up. "i better go make sure he doesn't burn the house down. we'll call ya in, g." He said, leaving a key in Gaster's hand that nearly fell right through. There was a message carved into the back.

"don't forget"

They shared one last look, before Gaster had his magic hands pick up the dummy and he walked outside, Sans walking in to help his brother.  
Then, Gaster took his chance, looking back at their souls. 

* * *

Inside the basement, Gaster had set down the dummy, and gripped the counter hard enough to crack it. His eyelights were out and he was struggling to contain his fury, his _hatred_ for the virus. It had done it. it had infected his sons. That was the final straw. he was going to find that thing and _annihilate_ it.

He took a few deep breaths, calming down. _Can't work angry, that just ruins the value of the work._

Once he'd calmed down, he started to tinker with the machine under the sheet. A doorway to parallel timelines was its original, intended purpose. This was followed closely by attempting to convert it into a gateway to the void. Unfortunately, it just never got there and was let in its broken state like this. Despite Sans' best attempts.

However, that didn't mean that nothing could be salvaged from it. That was how Gaster wound up holding a little stopwatch-like object with numbers like an odometer on the front. A device he had managed to figure out how to create while in the void. The upper line of numbers for total timeline resets, the lower for localized time loops. Resets and reloads. With both numbers set to all zeros, he could confidently start to work on the machine proper. It was the least he could do to try to help the him of this timeline. And perhaps, he could even repair it.

When he was called up, he had it so that it could at least power on. Sort of. It sparked. It was progress all the same, and he refused to give up on it. To him, there was nothing truly unfixable. Not a machine, or a situation.

Gaster was pulled inside by Papyrus, who certainly seemed eager. He was then sat down to a plate of what certainly looked like spaghetti. So he smiled at Papyrus, picked up his fork, and took a bite. If only he had been paying closer attention to the timelines.

The taste was indescribable, even to a scientist.

He forced himself to swallow, thanking any god there was that skeletons could not, to his knowledge, vomit. His smile was much more nervous now, and he was sweating. "Ah… This is…. A-amazing, Papyrus!" He said with a strained smile. "S-so amazing, that I couldn't bear to take another bite! You'd, ah, b-better save this for later!" Gaster said with a quick nod, pushing the plate away from him and trying to force down another wave of nausea. If he survived this, he was going to run some tests on that "spaghetti."

Papyrus simply chuckled, picking it up. "AH, YOU AREN'T THE FIRST TO HAVE THAT REACTION! MY COOKING IS AS GREAT AS I AM, AFTER ALL!" He said, scraping the pasta into a container, before placing it in the fridge. "OH, I NEARLY FORGOT! IT'S ALMOST TIME FOR METTATON'S BROADCAST! DADDY, COME JOIN US!" Papyrus shouted, grabbing Sans under his arm and vaulting the table to plop down on the couch.

Gaster sighed in relief, before following them with a wide smile and sitting on the opposite end as Papyrus, Sans between them. Usually Gaster had stopped watching by the time the human reached Hotland, as "runs" were usually firmly in place by there. When the screen turned on, Gaster had to force his eyelights to stay on.

There, on screen, was the human. The anomaly. The _virus_.

… Reporting the news?

 _Bombs?!_

The brothers seemed unfazed by this, besides the fact that it was the human. They were both, in fact, very very concerned for her. Unnaturally so. Oh he knew just why, but that made it no less unsettling.

"How did the hum– Er, Laura get on Mettaton's show?" Gaster asked after a moment of watching, noting the color of her soul. It was one of the four rarer colors yet with a common subtype. Fascinating. Her age, early twenties by his estimate, was also interesting.  
"he said he saw her on the cameras, then he just had to have her on his show. alph said it was like he became a brand new bot." Sans said, without taking his eyes from the screen. "thank god this is live, we get to see that the kid's alright for now."

Then Gaster's eyelights shrunk as everything clicked in his mind.


	4. HOTLAND

If Gaster had a heart, it would be pounding out of his rib cage right now.

As soon as he'd realized that the virus could infect through live video feed he'd teleported down to the basement, and was currently leaning against the counter. That was close, but it did give him something horrifying to think about:

The virus was transmitted through live video, as well as through direct contact. Which meant that _every single viewer Mettaton had was now infected._

This was, needless to say, very bad.

However, now he had something else: Laura's soul type and subtype. Respectively Passion and Perseverance. Gaster shook his head, opening a drawer. On it was a list of the soul types: red for Determination, blue for Integrity, aqua for Patience, green for Kindness, purple for Perseverance, yellow for Justice, and orange for Bravery. Those were the main seven, however, there were three more uncommon soul types: Gray for Cunning, pink for Passion, and black for Hatred.

However, ordinarily Passion-type souls don't act as _viruses_.

Something had to be causing this. Something abnormal. Gaster took hold of the dummy with his magical hands and left the had only started work on the modifications to it, but he couldn't stay here after that stunt he pulled. Leaning towards the window a bit, he could hear the almost obnoxiously loud "Death by Glamour," as Mettaton called it, blaring from the TV, though it was starting to taper off. That meant the human would be headed back home, soon. Which also meant that he could now safely see Alphys.

Gaster smirked, quickly walking north. He had a boat to catch, after all. 

* * *

"Hotland, please." Gaster said simply as he stepped onto the boat, the dummy held aloft behind him. The riverperson nodded once, and they sailed smoothly through the water.

" _Tra la la, your enemies are three not one."_

" _Tra la la, the one above, the one below, the one between."_

The scientist had long ago decided not to question the riverperson on what they meant. That only made more questions, rather than answers. But this information was bound to be useful. Three certainly made things harder, but for now, he had to focus on the threat at hand. _Laura._

They docked, and Gaster stepped off. "Thank you," He said simply before slowly, carefully peeking around. Coast was clear, so the scientist, like the dignified man he was, sprinted right up to the lab doors.

And ran into them with a resounding clang, having gotten there before they opened.

"👎✌💣 ✋❄📬" _{Damn it.}_ He said, voice muffled by the contact with the metal. Soon the door opened and he promptly fell forwards into the lab.

He remembered those being much quicker.

"O-oh my god, are you alright?!" A slightly nasally voice came, followed by quick footsteps to Gaster's side. He hadn't moved, and simply spoke from his position on the ground. "I'm fine. I've had worse. In fact, you know I've had worse, Alphys," He said, before slowly getting up. Thankfully his magic hands still had the dummy tight in their grip.

"Wh-what do y– G-G-Gaster?! O-Oh my G-God I thought you… H-how did you get back?!" She gasped out, doing an odd little panic dance. "W-we have to tell everyone! Especially K-King Asgore! A-and, then–" She started, before another magic hand clamped her mouth shut. "Alphys, please. Deep breaths, Calm down. Just like we used to do," Gaster said gently, Alphys nodding and breathing deep. "Secondly, we cannot tell anyone that I have returned. I have to do something _top secret_." He said as the hand released her. "U-um… Okay. Is there anything e-else?"

"Oh yes!" Gaster smiled wide. "I need your help to turn this into a robot. that runs on DT," He said, rather bluntly, bringing up the dummy.

"Wh-wh- _what?!_ "

"You always were the better one with robotics, after all. And you did figure out how to concentrate DT…" He trailed off, Alphys swallowing hard. "What w-would you even need something l-like that for?"

"Alphys. Can I trust you to tell _no one_ of this?" Gaster said after a moment, eyelights gleaming sharply, gazing into her soul. Her barely tainted soul.

… _What?_

"Y-you can t-t-trust me," Alphys said after a long moment, fidgeting under the skeleton's intense gaze. "Ah, thank you," Gaster said, toning down the magic of his gaze. "But… What happened with Mettaton? He didn't seem to be acting himself."

"You know a-about Mettaton?" The lizard monster squeaked. Gaster simply nodded, smiling. He was used to her nervousness. She used to be his assistant after all. He knew she wouldn't ask too many questions.

"W-well, he saw a, um, human on my camera feed, and then he just pushed me out of the w-way to watch it himself. Th-th-then he said he h-had to have her on his show… I hardly even got to see her," She said with a nod.

Gaster couldn't help but laugh. _Seems like the robot's ego spared my old assistant!_ "Ah, I see! But I suppose that is besides the point. Can you construct this robot?" He asked with no small amount of hope.

"O-of course! I just n-need a little time an–"

"Excellent! While you start that, I'll go handle the fuel." Gaster said, setting the dummy down.

Alphys nodded, starting to head up to her workbench with the dummy, when she realized just what Gaster said. "F- _fuel!?_ D-Doctor, what are you–?"

"I'll be back in a moment, Alphys!" Gaster called cheerily, as the secret elevator slammed shut, starting to head towards the deepest level.

"Oh no…" 

* * *

Gaster hummed to himself as he walked, the Amalgamates avoiding him. _Alphys had a chance to feed them this time._ He thought to himself as he reached the hall of mirrors. _She turned the entryway into my lab into this? Perhaps her guilt really was too much for her…_ He shook his head, magic hands sliding one of the mirrors out of place to reveal a hidden door. A quick code was all it took for that door to slide open as well, revealing a shadowy corridor.

And Gaster strode confidently into the darkness.

The rooms he had set up for the brothers, his sons, were still here. Makeshift bedrooms that allowed a degree of privacy, but with a door between them, and right by his office, of course. They had stayed there while he attempted to figure out how to explain them to the King. It was a very good thing that Asgore was such an understanding ruler.

He smiled softly, lightly rubbing the door's frame with a holed hand, before he pulled it back. _No. These aren't my Sans and Papyrus, no matter how similar they are. Don't get sentimental._ He took a breath, pushing away until he found his old office The blueprints for the extractor were still there as well as three syringes of DT.

Gaster took them all. 

* * *

Alphys jumped when the doors slid open. "D-Doctor Gaster! I-I–" She started, sweating and nervous. "Oh don't worry, they didn't give me any trouble. Glad to see everything's still up and running!" Gaster said with a laugh. "Now, let's get to work on that robot!"

"A-about that… It's, uh, done?" Alphys said slowly, and Gaster froze on his way up, the escalator carrying him the rest of the way. "Done? What?" _I knew she worked fast, but not that fast!_ He thought, looking over at the robot.

Gaster then had to stop himself from annihilating it. The machine was, albeit with a few differences, a dead ringer for a certain genocidal human.

"Oh it m-much easier to build when I-I have a base to work on," She said, laughing nervously. "D-do you like it…?" Gaster had to take a moment to calm down, before giving her a gentle smile. "It's amazing, Alphys, thank you. Now then," He said, magical hands lifting the robot up. "Before I put this to work, I'll need to meet with the king. I hope you don't mind if I take this with me?" He asked, smiling gently.

"Oh, um, n-not at all, D-doctor. But… Didn't you say it was t-top secret?" Gaster frowned at that, sighing. "It is, Alphys, but I still need to let King Asgore know." He said, starting to head towards the door. "And don't worry! I'm sure you'll get Captain Undyne yet!" He called over his shoulder, just before the doors slammed behind him. Inside the lab, Alphys had turned beet red and fainted.

Gaster took a deep breath of the heated air of Hotland. It was time to head for New Home. It was good to know that Alphys was doing alright, though.

Even if he had to lie to her.


	5. NEW HOME

Bells chimed as Gaster stepped into the golden hallway. The Last Corridor. The Judgement Hall.

The skeleton took a slow breath. This place… This place had seen horrific violence, and shining beacons of hope. But above all, this was the place where sins were weighed, and unshakable Determination was tested. The hall was solemn.

Gaster gently set the robot down behind one of the last pillars, removing the modified soul container from its back. It was a very good thing he deflected the question of why he needed it. This was not going to be pleasant. Gaster took another slow breath and started to walk towards the exit to the hallway, when the sound of ground shifting came behind him.

"Howdy! You're planning something, aren'tcha?" The almost sickeningly cheerful voice said.

"Hello, _Asriel_." Gaster said, without turning around. Flowey flinched. "… You really think you know a lot, don't you? Well you're just an idiot like the rest!" The soulless plant shouted. "You know she's unstoppable, a soul with determination like hers… You can't match it, can you?" Gaster simply chuckled in response. "With all due respect, _prince_ , I'm the one with the Ph.D." Gaster said, turning around, his eye sockets shut. "So please, Asriel, let me help you. Because, if the human is allowed to live, the consequences will be…"

His sockets opened to reveal pitch black voids. "" _ **{Dire.}**_ _  
_

Flowey, despite his soulless nature, let out a rather terrified squeak and proceeded to retreat into the ground. If he couldn't be Sans, how was he supposed to beat the guy's father?! Gaster sighed, eyelights reigniting. He pitied the prince, he truly did, but he had work to do and the goat-turned-flower's involvement would just complicate things.

It was only a few moments before he reached the throne room. He could hear Asgore inside, tending to his flowers. He took a deep breath. This was going to be hard. He didn't want to do this, and this was really a last resort, because he couldn't go near the virus. He took a last breath, and promptly turned sharply and walked downstairs.

Every click or clack of his shoes on the stairs bounced and echoed off the gray walls as he descended to the final resting place of the seven fallen humans. The air down in that narrow room was cold and musty, combined with the fact that none of the sound from the rest of the grounds usually reached this place, it gave the room a rather foreboding feel. "I apologize… But I require your help." He muttered, walking up to the coffin engraved with the name of the first fallen human. _Chara_.

It was empty.

… _Why was it empty?!  
_

Suddenly, Gaster realized. _Toriel!_

* * *

Gaster, holding the canister, blinked back into existence next to the flowerbed where all those who fell into the underground landed. And where the first was buried. It had taken quite some to try to get the location of the first child's remains. But now he was here.

His plan was simple. he couldn't fight the virus on his own, and any monster that got near her would be infected. Therefor, he needed someone who wasn't a monster to fight her. However much he loathed this option. He gently set the canister down and took a deep breath. " **Chara.** " He said slowly.

…

 _ **But nobody came.**_

Gaster narrowed his eye sockets. That wasn't right. In her own words, that were admittedly hard for him to view given she appeared to be talking to thin air, she was bound to come when her name was called. So why wasn't she here? Unless… _She's already bound to Laura. Damn it!_ That was his main plan ruled out, but there was always another way. He could still faintly detect the magic of his gray door. The doorway between timelines. And he needed a strong fighter…

Gaster was hating this option the more he thought about it, but it was the only way. He pulled out one of the DT syringes, and rammed it into one of his ribs. The skeleton hissed with pain as he felt the thick, burning liquid flow into his magic stream, and his eye sockets lit up with bright red magical irises again. Immediately he tossed the syringe away and focused on the door, willing it back into existence with all his magic and the Determination burning through him.

Gaster took hold of a doorknob.

The door was flung open into pure darkness. Pure _nothingness_ with one exception. A pulsing, dark red soul floated in the center. The price paid. It was strained, but he got his voice to work, along with a magical hand to drag the soul over. He didn't even realize his ability to speak in normal text had eroded away.

"👍 ✌ ✌📬" **{Chara.}**

The door slammed and the heavy rush of sheer Determination left Gaster on his hands and knees, panting, as it faded. " ✞ 📬📬📬 👎 ✋ ❄ ✌❄📬📬📬 ✌ ✌✋ 📬📬📬" _{Never… doing that… again…}_ He muttered, before looking up. _Chara. LV 20. Determination, subtype Hatred._ His mind automatically filled him in on what he already knew of the tainted soul before him. Then said soul did something unexpected.

Wisps of sheer Determination flowed off of it, forming up into the rough outline of a perpetually smiling little girl. " **Greetings. Why have you called me here, old man?** " Chara asked, her mouth not moving as she spoke. The girl's voice was light and airy. Gaster slowly stood, brushing himself off before facing the demonic child. Or rather, looking down at her, as he was quite a bit taller than she was. Before he spoke, he had to swallow hard, as if he was both gulping down his pride, and the venom that he felt towards her. "✌💧 💣 👍 ✌💧 ✋ ✌❄ ❄ 💧✌✡ ✋❄📪 ✋ 👎 ✡ 📪 ✡ ✋❄❄ ✌👌 💣✋ ✌❄✋ 📬" _{As much as I hate to say it, I need your help, you little abomination.}  
_

At that, Chara started to laugh. " **Oh that was good, old man, but I thought your son was the only one who told bad jokes. Or at least, he used to be.** " Gaster grit his teeth. She was getting on his nerves, but he had to stay calm. "✋ ✌💣 👌 ✋ 💧 ✋ 💧📪 👍 ✌ ✌📬" _{I am being serious, Chara.}_ He said, and the demonic girl gave him an almost bored look, her resting smile dipping a bit. " **And why would I help you?** **You are lucky enough that I am one of the few that can understand you.** "

"✡ ✌ ❄ ❄ 😐✋ ✌ 💣✌ 📪 👍 👍❄✍" _{You want to kill a human, correct?}_ She perked up right away.

" **You have my attention.** "

Gaster took a deep breath. "❄ 💣✌ ❄ ✋💧 ❄✋💣 ✋ ✋💧 ❄ ❄ ✡ ✌ 💧 👎 ❄ 📬 ✋❄ ✋💧 ✌ 💣✌ ✋💧 💧 ✡ ✋ 👍❄✋ ❄ 👎 👎📬 ✋ 👎 ✡ ❄ 😐✋ 📬" _{The human of this timeline is not the one you are used to. It is a grown woman who is slowly infecting the underground. I need you to kill her.}_ Gaster said slowly. Chara paused, her eternal smile falling into a thin line as she looked off to the side, seemingly at something Gaster couldn't see. After a moment of this, she grinned once more.

" **Very well, old man. I accept. You have a body for me to inhabit, correct?** " The skeleton nodded. "✡ 💧📪 👌 ❄ ✡ 💧 👎 ❄ 👌 ✋ ❄ ✋💧 👍✌ ✋💧❄ 📬" _{Yes, but your soul needs to be in this canister.}_ He said simply, magical hands bringing the mentioned object to his physical ones.

Chara looked at it for a moment, before nodding, the Determination that made up her "body" slowly flowing back into her soul. As soon as it was clear, he canned it, and warped it back to the corridor, by the robot. He would put the two components together soon, but first, he needed to handle something else.

That little abomination could wait. 

* * *

The scientist reappeared in front of the skeleton brothers' home in Snowdin, knocking on the door. Five minutes later, Sans answered the door. "g? what happened? you just kinda bolted before." Gaster sighed. "✋ ✌ ✋ 📪 💧✌ 💧📪 👌 ❄ 💧 💣 ❄ ✋ ❄ 👍✌💣 ❄ ✌❄ ✈ ✋ 👎 💣✡ ✌❄❄ ❄✋ 📬 ✞ 📪 ✋ 👎 ✌ ✌✞ 📪 ✋ ✡ 👎 '❄ 💣✋ 👎📬" _{I apologize, Sans, but something urgent came up that required my attention. However, now I need a favor, if you don't mind.}_ Sans raised a brow ridge. "uh, sure, g, but might have to wait a bit. laura ended up passed out in the cold on the way to the ruin's and she's ko'd in pap's bed." Sans said, before adding on "oh, and what happened to your voice? thought you could speak without all the wingdings."

"💧 '💧 ✍" _{She's here?}_ He said, very briefly entertaining the option of teleporting past Sans and destroying her now. However, he dismissed that plan when he realized that the virus would most likely try to defend itself by infecting him, and Sans most likely wouldn't take too kindly to that.

He may not know his HP value at the moment, but he knew _that_ was a fight he didn't want, for more than just his own health.

" ✞ 💣✋ 👎📬 ✋❄'💧 ❄ ✋ ❄ 👌 👍 👍 👎 ✌👌 ❄📪 ✌ ✡📪 💧❄ ✌ 💣✋ 💣✋💧 ✌ 📬" _{Never mind. It's nothing to be concerned about, really, just a minor mishap.}_ And heaven knew those happened often enough around the good doctor. "✌ 👎 ✌👍❄ ✌ ✡📪 ✌ ✌ 👌 ✋ 💣✌😐 💧 ❄ ✋💧 💣 👍 ✌💧✋ 📬 💧 ✌😐 💧 ❄ ❄ 💣 ❄ 💣 ✋ ❄ ✌💧❄ 👍 ✋👎 📬 ✌✞ ✌ ❄ ✋ 💧 👎 ❄ 👎✋💧👍 💧💧📬" _{And actually, Laura being here makes this much easier. When she wakes up tell her to meet me in the Last Corridor. We have a few things we need to discuss.}_ He said simply. "sure thing, g. she'd love to meet you." Sans said, his own permanent smile almost seeming to grow a bit at her mention.

It made Gaster sick.

"❄ ✌ 😐 ✡ 📪 💧✌ 💧📬 ❄✌😐 👍✌ ✌ ✡ 💧📪 ✌ ✋ ❄✍ " _{Thank you, Sans. Take care of Papyrus, alright?}_ He said, before teleporting again.

He so hoped that his plan worked.


	6. LAST CORRIDOR

Laura yawned and sat up in the unfamiliar bed, stretching before her eyes shot open. This wasn't her bed at home with mama goat.

She blinked, before giggling to herself and brushing her black bangs from her face. Looks like Pap let her have his room while he was out training with Undyne.

Her eyes were odd, she thought, for what had to be the hundredth time in her life as she looked at them in the blank screen of Pap's computer. Her eyes were brown, but with a fair bit of pink mixed in.

That little girl's voice in the back of her mind had been oddly silent, and she left Laura's dream part way through instead of staying the whole way. Something was wrong, but she couldn't put her finger on what.

Oh well, she had to head home anyways, she didn't get the chance to call Mama Toriel last night. And she still didn't know why she called the old goat mama so readily. Question for another day, it seemed. She pulled on her black and pink, MTT-brand, striped jacket and gave her hair a few quick brushes so it curled on her shoulder before leaving Pap's room. She then proceeded to nearly bump into Sans.

She let out a rather undignified squeak and fell back on her rear. "I thought I told you to stop doing that!" She shouted, a blush creeping along her face. His only response was a chuckle and a shrug, his eyelights gleaming pink for a moment. "when you stop bein' cute, i'll quit it." He said with little skeletal finger guns. Laura just huffed, crossing her arms. Girl was very much a child at heart.

"Well if you're done, I gotta get back home now!" She said standing, only for him to put a hand on her shoulder. "oh, there was one more thing. an, uh, old friend of mine came by earlier, said he wanted to meet up with you in the last hallway before the throne room. said it was important." Sans said with a nod, voice uncharacteristically serious.. "you should probably go. if he thought it was important, it's probably, well, pretty darn important, if you get me."

"Oh, well, uh… I guess? Let me just call Mama first…" She looked down at her phone to dial the number, but when she looked back up, Sans was gone. _How does he do that?_ She wondered as the phone rang. On the third ring, Toriel picked up. "Oh, I was getting worried, my child! Thank you for calling." The old woman's voice was very relieved, from what Laura could pick up.

"Hi mama. Sorry I couldn't call earlier, I was a little… preoccupied. But Sans and Papyrus took good care of me!"

"That is good to hear my child, I will go open the doors for you."

"Actually, um, Sans wants me to meet an old friend of his? He says it's important, so…"

"Oh…" Toriel sounded rather distraught, but nodded. "If you insist, my child."

"Don't worry, mama, it shouldn't take too long, so I'll be back home soon!" She said trying to cheer Toriel up. People really have been getting pretty attached to her, but at least after that visit with Gaster in Waterfall, she knew why.

According to the melty scientist, her soul had been altered in some way when she fell into the Underground, causing her to force people to like her without even meaning to. Laura sighed. _I just want to be normal…_

* * *

The boat ride was quick, if unnerving. _Beware the man who speaks in hands…_ Were they talking about Gaster? He certainly seemed nice enough when she met him, if a little hard to understand.

Laura shook her head. She had a meeting to get to! She quickly thanked the riverperson before heading off. It was a few quick elevator rides and a rather long walk, but after a while she was there, in that golden hall.

There was someone else there.

A small child, probably a little girl, stood on the opposite end of the hall from Laura, her eyes glowing a dull red that allowed Laura to see both even though her left side was coated in shadows due to the light from the large windows. She was holding something in her left hand.

" **Greetings.** "

Laura flinched at that voice. It was so similar to the one in her head, but so much… colder. Even less caring. The voice in her mind had wit, a bit of dry humor. This girl had neither, and Laura couldn't shake the feeling of dread she got from looking at the child.

"Um… Heya! I'm L-Laura. Sorry, I'm a little more composed than this usually." She laughed nervously. "What's your name?"

The child took a step closer, dead silent.

This was getting to be extremely unsettling.

"Are you Sans' friend?" She tentatively asked.

The child stopped, and let out a long, cruel laugh. Then she took another step. Now she was close enough that Laura could see she wasn't really a little girl, more like a robot. Like Mettaton.

"Y-you're really freaking me out, here, girl…" Laura said, trembling. She took a step backwards and looked over her shoulder. The entryway was blocked by a wall of bones.

The girl raised her left hand, and the object in it caught the light. A kitchen knife.

Laura's breath caught in her throat.

" _ **COME.**_ " Chara intoned, before rushing the human, knife raised. 

* * *

Within the Void, within the gray room connected to this infected timeline, a partially melted man watched the events unfold in the golden hallway with interest. This supposedly impossible duel raged with slashes and dodges. The human was still alive.

That was good.

The man was deliberately ignoring the way the pink branched off to other timelines. Ignoring the way the newly infected timelines ended abruptly and were then totally annihilated, only to have the burnt-out husks start spreading new pink tendrils out.

That didn't matter.

What mattered was that Sans and Papyrus were alive and safe. After all, his timeline was fine, and they were fine. This was clearly much better than gambling with a child, right?

Right.

The other timelines didn't matter. The pink in their souls didn't matter.

The heavily glitching pink in his soul didn't matter.

Sans and Papyrus were safe.

The rest was…

 _[Unimportant.]_


	7. DARK DARKER

The slashes came wickedly fast, seemingly leaving a faint red trail behind them as that kitchen knife carved through the air towards Laura.

The human, extremely thankful that her reflexes were sharp, was immediately forced onto the defensive from the murderous robot. She had to dodge slash after slash, some getting far, far too close for comfort. _Overhead, from the side, cross up, sweep, stab, that's a feint!_ Her mind shouted as Chara mercilessly rushed her.

After over a dozen slashes, Chara leaped backwards, giving them some distance. " **Hm. This is not nearly as exciting as I thought it would be.** " She mused, twirling her weapon expertly before leveling at Laura once more. " **Why won't you fight back? You are like the Comedian, if he didn't murder me dozens of times. Like Frisk. Always dodging. Never fighting. Fight me. Now.** "

Now, ordinarily, Laura would've fought back; instinctively, if anything, from the crippling fear that this thing caused in her. However every time she thought about it, a thought would come to her head that told her that attacking this demon would be about as useful as trying to kill Undyne with a firm handshake. "A-are you talking about Sans? What do you mean he killed you? Who's Frisk?" She asked after a moment.

"… **You cannot hear them, can you? Pathetic.** " Chara said after a moment of thought. " **You will not fight back and you cannot hear them? You are truly worthless.** _ **Die**_ **.** " Chara practically growled, rushing towards Laura again. The girl screamed and another harsh barrage of knife strikes came, Chara's LOVE-powered soul and robotic body untiring. Unfortunately, Laura had neither of those things, and slipped up, receiving a harsh slash across her left arm. She shouted in pain, blood staining the ripped jacket as she staggered and fell. Chara, however, was smiling wider than ever, despite stopping her furious assault.

" **You survived one of my attacks? Interesting. Perhaps there is some use in you after all. I will enjoy watching you die.** " Chara said, tossing her knife up into the air, Laura's focus on the blade, only for Chara to catch it and immediately attempt to bury it in the human's chest. A quick roll from Laura was the only thing that saved her, Chara ripping the blade from the ground. "Why are you doing this?!" Laura shouted, confused. Chara, naturally, responded by trying to plunge the knife into her again, forcing the woman to scramble away towards a pillar. it was an odd sight, a little girl putting someone in her mid-twenties on the defensive for fear of her life.

With the arm that wasn't severely injured, Laura fished out her cell phone, sending a panicked text to the first person she could before her phone, and hand, were pinned to the pillar by the kitchen knife piercing through them.

Chara grinned as Laura screamed.

 _Ping!_

Chara's blood red eyes, even being the LEDs they were shrunk. She knew that sound. She knew it all too well.

That was the sound of blue Integrity magic wrapping around a soul.

" _ **NO!**_ " She roared, yanking that knife out and attempting to plunge it into Laura's heart before gravity abruptly shifted for her, slamming her against the opposite pillar. Reflexes honed sharp from dozens upon dozens of replays of the same fight made her jump just in time to avoid the bed of bones that erupted from the pillar to skewer her. Abruptly, Chara's gravity returned to normal, turning her jump into a lunge and roll. Her red eyes narrowed, glaring daggers at the short skeleton who was standing before her, having teleported in. "heya, kid. i'd say it's _knife_ to see you, but…" His eyelights extinguished and a pair of blasters appeared behind him. "we both know that'd be a lie."

" **Stay out of this, Comedian.** " Chara snarled, leveling her knife at Sans, the intense emotion unusual for her. " **You'll have your turn after I butcher her.** "

Sans shrugged. "i think i'll take mine first. so from that expression, i told you to count for me, didn't i? what'd we get up to?" He asked, his smile now much more vicious than jovial, despite not moving an inch.

" **One hundred fifty-eight.** " Chara replied without a second thought.

"huh. a hundred fifty-eight to one. that's a pretty bad track record, y'know? but i guess you never gave up. alright then." He shut his eyes, Chara's soul turning blue once more. "wonder if you'll quit by two hundred." He swung his arm out, immediately tossing Chara to the side with a gravity shift before the bed of bones came back up. In fact, he outright reused the attack he'd attempted to blindside her with. " **Do you really think I'd fall for tha–** " Chara started, only to turn and come face to face with a gaster blaster. Which immediately fired, followed up by the ring of other blasters he summoned while she was being hit by the first. The metal body melted, then was vaporized under the intense attack.

Her soul cracked in half, then shattered. The blasters reduced the shards to ashes. Sans slipped his hands back into his pockets. after wiping away some sweat that formed on his skull. "welp. guess that's that. sorta easier than i expected." He said, shutting his eyes and waiting for the reload. What came was a bit shocking in how different it was.

" ✏" _{No!}_

* * *

 _This wasn't right. This wasn't supposed to happen. Chara was supposed to win. Chara_ _ **always**_ _won!_

Gaster's mind was racing, in his sheer disbelief, he'd jumped out from his hiding place behind one of the last pillars. And drawing all the attention to him.

 _Oh_ _ **no.**_

"oh, there you are, g. was startin' to wonder if that little freak got you too." Sans said with a little wink. Gaster had to think fast. " 💧✌ 💧📪 ✋ 💣 ✋ 📬 ✌❄ ✌ 👎 ✍" _{No Sans, I'm fine. What happened here?}_ Feigning ignorance was the best option he could see.

It was an odd, sickening feeling to hope that the virus had dulled Sans' legendary perceptiveness.

"well we got a little… friend there." Sans said, nodding at the scorch mark on the floor, all that was left of Chara. "that had to be dealt with. a _genocidal_ friend." Sans's voice dropped an octave, eyelights flickering out for a moment. "✋ 💧 📬 ✋ ✌👎📬📬📬 ❄ 💧 ✌😐 ✋❄ 😐✋ ✌💧 ✌ 💣 💣 ❄📪 ❄ ✋💣 😐 ✋ ✌👎 ❄ 👎 👌 👍 💣✋ ✋ 📬 ✋ ✋ ✌👎 😐 📬📬📬" _{I see. I had… Gone to speak with King Asgore for a moment, let him know I had returned before coming in. If I had known…}_ He shook his head, desperately hoping he was a better actor than Alphys. He could feel sweat beading on his skull as Sans looked back up at him.

"ah, i get ya, g. anyways, kid's still safe, but maybe I should stick around." Sans said with another shrug and a wink. "in case we get any other _visitors_ , ya know? anyways, c'mon out kid, gaster isn't gonna hurt ya." He said, looking over his shoulder at the pillar.

A moment later, the bloodied girl walked out into the open and Gaster felt himself lock up. _Oh no. This is it._ He shut his eye sockets and waited. For what, he wasn't exactly sure. Maybe a tingling feeling as his soul was swallowed up?

"Gaster…?"

Nothing happened.

He opened his sockets and looked down, willing his soul out, much to the confusion of the other two. "uh, g? what are you doing?"

No pink. No corruption.

His mind was racing. This went against everything he knew, before it clicked. He wasn't from this timeline. A wide smile spread on his skull. He was _immune_.

"✌ 📪 💣✡ ✌ ✋ 📪 ✋ 💧✋💣 ✡📬📬📬 ✌👎 ❄ 👍 👍😐 💧 💣 ❄ ✋ 📬 ✌ 👎 💧💧📪 ✋ ❄ ✋❄ 👍 💧💧✌ ✡ ❄ ❄ ✡ ❄ ✌❄ ✋ ✌✞ 👍✌❄ 👎 ❄ ✞✋ 💧📪 💧✌ 💧📬" _{Ah, my apologies, I simply… had to check something. regardless, I felt it necessary to tell you that I have located the virus, Sans.}_ He said with a nod, moving back into character and movign his soul back into his body. "well that's a relief. but might need to explain that to the kid." Sans said, pointing over to Laura with a thumb.

"You didn't say anything about that in Waterfall…" She mumbled, looking up at him. " ✌❄ 📫📫 ✌ ✋ ❄✏ 📪 ✋ 👎✋👎 '❄ ✋💧 ❄ ✌ ✌ 💣 ✡ 📬" _{Water– Ah right! Well, I didn't wish to alarm you.}_ He said quickly, hoping his smile was convincing. "✋❄ ✋💧 ✌ ✞✋ 💧 ❄ 💧 📪 ❄ ✌❄ ✌ ❄ 💧 ✌ 👎 👍 ❄💧 ❄ 💧 ✌ ✋❄✋ 💧 ✌ ✋ 👍 ❄✌👍❄ ✋❄ ✋❄ ❄ 💧 ✋❄ ✋❄💧 ✋💣💧📬 ✌ 👎 ❄ ✌❄ ✋ ✌✞ 👎✋💧👍 ✞ 👎 ✋❄💧 💧 👍 📪 ✋ 👍✌ ✋💣✋ ✌❄ ✋❄ 👎📬" _{It is a virus of the soul, one that alters and corrupts the personalities of all in contact with it to suit its whims. And now that I have discovered its source, I can eliminate it for good.}_ Gaster said, before taking a deep breath, Laura standing in shocked silence. Something about this sounded familiar to her.

"💧✌ 💧📪 ✌💧 ✌✞ 📬" _{Sans, please leave.}_

"what? g, you know i made a–"

" 💣✋💧 📪 ✡ 💧📪 ✋ 👎 😐 📬 👌 ❄ 💧✌ 💧📪 ✡ 💣 💧❄ ❄ 💧❄ 💣 📬" _{Promise, yes, I do know. But Sans, you must trust me.}_

Sans looked rather distressed, leaned back and eyelights flicking back and forth between Gaster and Laura. Then his soul pulsed with pink. "… sorry g, I can't." He said, at length, drawing a sigh from the taller skeleton. "✋ 💧 📬 ❄ ✌❄ 💣✌😐 💧 ❄ ✋💧 💧 💣 👍 ✌ 👎 📬📬📬" _{I see. That makes this so much harder…}_ He said slowly, eye sockets closing. " ✌💧 📪 💧❄✌✡ ❄ ❄ ✌✡📪 💧✌ 💧📬" _{Please, stay out of the way, Sans.}_

"what are you–"

Gaster swung his left arm out, blue magic gripping Laura's soul and changing her gravity to slam her against the wall, forcing out a yelp of pain. It was only memory of what the demon-possessed robot did that saved her from getting skewered on bones. A pair of his own blasters formed at the scientist's sides, aimed at Laura with energy pooling in their maws. Gaster's eye sockets were open now, his use of such powerful magic activating the magic irises in them, which flickered between purple and red. Perseverance and Determination.

"gaster, what the hell are you doing?!" Sans shouted, a pair of his own blasters taking the beams for the human. "💧✌ 💧✏ ✋ ❄ 👎 ✡ ❄ 💧❄✌✡ ❄ ❄ ✌✡✏" _{Sans! I told you to stay out of the way!}_ Gaster shouted.

"well I can't let you kill her!"

"💧✌ 💧📪 💧 ✋💧 ❄ ✞✋ 💧✏" _{Sans, she is the_ _ **virus**_ _!}_

Sans' eyelights snuffed out, magic faltering. "… what?"

Gaster took that empty moment to fire another beam at Laura, who was trying to hide behind a pillar. "✡ ✌ 👎 💣 👍 👍❄ ✡ 💧✌ 💧📬 💧 ✌💧 ✋ 👍❄ 👎 ✠❄ ❄ ✞ ✡ ✋ ❄ 👎 👎 ✌ 👎 ✋ 💧 ❄ ❄ 👍 ❄✋ ❄ 👎 💧 ✏" _{You heard me correctly Sans. She has infected next to everyone in the underground and I refuse to let her continue to do so!}_ He shouted, magic flaring again as he slammed her against the opposite wall, a pair of blasters taking aim at her. Her soul flickered, and her gravity was changed once more sending her to the ceiling and out of the way of the lasers. Sans' left eye was glowing with Patience and Justice, though with a distinct pink outline.

"Could you maybe warn me first?!" She called out with a little whimper before he let her fall back down to the ground to avoid the bed of bones threatening to impale her. "Please, Gaster! I don't know what you're talking about!" Laura cried out after having to roll on her bad shoulder to avoid yet another laser. Gaster faltered for a moment, before sending a wave of bones at her.

A wave of bones that was obliterated by a laser that Gaster had to sidestep.

"💧✌ 💧📬📬📬 ✌❄ ✌ ✡ 👎 ✋ ✍" _{Sans… What are you doing?}_ Gaster asked slowly, eyelights shrinking in horror as he saw that the laser had, in fact, been meant for him. "g… if you want to hurt her, you gotta get through me, first." Sans said, voice ringing with a dark finality.

"💧✌ 💧📪 ✋📬📬📬" _{Sans, I…}_ Before Gaster could finish, an utterly massive bone crashed through one of the barricades he had set up to keep Laura in. "SANS! LAURA! I HAVE ARRIVED! I'M SORRY I COULDN'T SOONER, BUT SANS ALWAYS WAS BETTER WITH HIS SHORTCUTS." Papyrus said, and then he took in the scene in front of him. Broken bones, laser marks, and charged blasters aimed at each other, with Sans and Gaster as the owners.

"papyrus, get out of here!" Sans shouted, looking back at the younger skeleton. Unfortunately, Gaster took this as a chance and fired from above. If the virus was going to force others to fight for it, he wasn't about to fight fair.

Laura was, once more, yanked out of the way of his beam by blue magic altering her gravity, but this time she landed right in Papyrus's arms. Papyrus, whose right eye had a burning, orange and green magic iris in it. Bravery and Kindness.

"FATHER, BROTHER. I MAY NOT KNOW WHAT'S GOING ON RIGHT NOW, BUT I DO KNOW ONE THING. I CANNOT LET YOU HARM LAURA." Papyrus said with a resolute nod. Sans swiftly teleported to his side as Papyrus set down Laura behind him. "pap, i hate to say it, but g's gone a little nuts. he's tryin' to kill the kid." Sans said quickly, readying himself for a battle. "I SEE. IT PAINS ME TO DO THIS, FATHER, BUT I CANNOT LET THIS CONTINUE. I WILL STAND WITH SANS AGAINST YOU, HOWEVER MUCH IT PAINS ME TO DO SO."

Gaster staggered, eyelights just pinpricks in his sockets. _No… No, no no!_ He shook his head "✋ ✋ ❄ ✋ ❄ ✡ ❄ ✏" _{I will not fight you two!}_ He said, immediately after sidestepping another laser, this one sent by Papyrus. _Sans must have taught him that._ Gaster mused, before he felt a weight in his very soul. He'd seen that twisted show far too many times not to have Sans' opening attack down. Jump, dodge the waves of bones, directional blasters. Not a scratch on him.

" ✌💧 📪 💧✌ 💧📬 ✋'✞ 💧 ❄ ✌❄ 💣 ✞ ❄ 💣✌ ✡ ❄✋💣 💧 ❄ 👌 ✋❄ 👌✡ ✋❄📬" _{Please, Sans. I've seen that move one too many times to be hit by it.}_ Gaster said calmly, before nearly being blindsided by a flurry of bones from Papyrus. "👌 ✡💧📪 ✌💧 📪 ✋ 👎 '❄ ✌ ❄ ❄ ✋ ❄ ✡ ✏ ✞ 📪 ✌ ✌ 💧❄✋ ✌💧 ❄ 👎✋ 📬" _{Boys, please, I don't want to fight you! However, Laura still has to die.}_ He said, Papyrus having to pull Laura out of the way of yet another bed of bones.

This was immediately responded to with blasters from the brothers, Gaster having to perform one of Sans' flash-sidesteps out of the way of them, before jumping as bones sprung up underneath him. He still didn't know what his HP was, so he couldn't take any chances, staying on the defensive. A spinning bone blocked one of Papyrus's blasters while a laser of his own destroyed a wave of bones sent by Sans.

However, the defensive was, honestly, getting him nowhere. That combined with the fact that Laura had forced what technically were his sons against him was starting to get the scientist angry. Angry enough that a pair of giant magic hands grabbed both skeleton brothers and forcibly pulled them to either wall, doing zero damage from a lack of killing intent. Something that sickened him to see the virus had forced the brothers to use against him. "✋ ✋ ❄ ✌✞ 💣✡ 👍 ✋ 👎 ❄ 👎 ✌ ✌✋ 💧❄ 💣 ✌ ✡ ✏" _{_ _ **Enough**_ _! I will not have my own children turned against me any longer!}_ He shouted, magic eyes flaring as he forced Cunning magic onto the fleeing human's soul, painting it gray and inverting her movement. "Gaster, please! You told me that I was better than the other human!" Laura shouted, seeing as she had no other options left. This was wrong, she was usually right when it came to this. She had his own word to go by.

Gaster paid her no mind. _This virus will say anything to survive_. He thought, a blaster forming over him, aimed down at her.

" _Stay away from my child!_ "

Gaster had just enough time to erect a wall of bones before the fire was on him, seeping in through the holes of his barrier and washing over him. It was utter agony, the sheer intent behind them forcing the heat of the flames higher. Gaster shut his eye sockets. He was sure this was it, to die a pile of ash on the floor, so close to accomplishing his goals. To saving everyone.

 _ **80094**_

Gaster blinked. _What?_ That absurd damage, but he wasn't dust. Finally, he could see his HP in front of him, as could everyone else. The battle had stopped.

 **HP: 586572/666666**

A grin worked its way across Gaster's skull as Toriel took a shocked step back. "✋❄ 💧 💣💧 💣✡ ✌ ✋ ❄ ❄ 👍 ✌👎 ✌ 💧✋👎 👍❄📬 ✋ ❄ 💧❄✋ 📬 📬" _{It seems my fall into the CORE had a side effect. Interesting. Well.}_ Gaster brushed himself off, standing straight. "❄ ✋💧 💣✌😐 💧 💣✡ 👌 ✌ ❄ ✌💧✋ 📬" _{This makes my job a lot easier.}_ He said with a laugh, magic eyes flaring up once more as he brought back the gray magic over Laura's soul, locking her in place.

Fireballs and bones smashed against him, but he paid them no mind. They hardly put a dent in his astronomical HP pool regardless. Even when the blasters came he didn't even slow down in his march to where Laura was cowering, though he did appreciate the difference in the brothers' attacks. Sans' strikes shredded through you, dealing minimal damage, but hitting thirty times per second. Papyrus, however, simply had his strikes hit once, with their full power behind them, in a more traditional attack. Even his lasers hit that way.

Gaster really had time to appreciate this when he waded directly through one of Sans' increasingly panicked lasers that had been placed directly in his path and manually flung it aside, one of his own slowly charging overhead. Gaster, however, should have paid much more attention to his HP, as when he was ready to fire he realized something. Something very bad. Something that onslaught had done to him as the panic got to the brothers.

 **HP: 250/666666**

His eyelights were pinpricks as heard Toriel roar, as he felt the flames wash over him once more, dealing undoubtedly fatal damage.

 _No… NO!_

He refused to let it end this way. Gaster reached into his coat, withdrawing one of the syringes of Determination and injecting it into himself even as he felt his bones starting to dust. Suddenly energy was flowing through him, his body reforming, but starting to ooze. "✋ ✋ ❄ 👎✋ ✏ ❄ ✏ ❄ ❄ ✋💧 👍 💧 ✏ ✋ 💧 ❄ ✏" _{I will not die! Not now! Not this close! I refuse to!}_ He shouted, body beginning to lose its solidity. In the back of his mind, a long forgotten scene played. A scene of a powerful warrior screaming to the heavens that she would not die, that she would prevail, even as her body gave out…

Another fireball slammed into him, forcing him to pull out the last syringe, his magic irises now pure red, even as his right eye began to droop shut. New Determination filled him as he focused his power, the energy in the blaster's gaping maw turning a bloody red. An instant kill attack.

"lady, stop! he can't take anymore!"

"PLEASE, LADY ASGORE! I KNOW OUR FATHER IS UNWELL, BUT THAT'S NO REASON TO KILL HIM!"

Toriel shut her eyes, the pink in her soul burning bright as she cast another column of fire at the melting scientist. Her soul was almost entirely eclipsed by it, it was like she was for their father had pushed Sans and Papyrus' souls free of that infection, so the virus hard focused all of its power onto Toriel.

"✋ 👍✌ ❄ 👎✋ ✏ ✋ ✋ ❄✏ ✋ 💧 ❄ ✌ ❄ ✋💧 ❄ 👍 👍😐 👎✏ ✋ ✋ ✋ ✋💧 ❄ ✋💧✏" _{I cannot die! I will not! I refuse to allow this to go unchecked! I will finish this!}_

Gaster's arm trembled in its raised position, dusting and melting at the same time. flames washed over him.

His vision went white.

 **…**

A small breeze blew through the battle-stricken corridor and its unmoving inhabitants, slowly sweeping away part of Doctor Gaster's dust.


	8. YET DARKER

Gaster's eye sockets shot open as he gasped. This couldn't be real. This was impossible. He had _died._

And yet here he was, the canister containing the Fallen's stolen soul in hand, about to put it in the robot. " **Huh. I didn't think you had it in you, old man.** " The stolen soul chimed into the scientist's thoughts, the smile audible from her tone. "📬📬📬 ✋💣 💧💧✋👌 📬 ✋ 👍 👎 ❄ ✌✞ 📬" _{… Impossible. I couldn't have.}_ Gaster said softly, reaching into his coat. That innocuous little device, the one he'd created back in Snowdin, he now clutched like a lifeline. The first line, the one that measured total timeline resets, was all zeroes. The second, that measured localized time loops…

00001

" **How does it feel? You reloaded. You really pushed yourself over the edge for that one, huh?** " Chara's vaguely mocking voice came once more, only to cause a smile to play across Gaster's skull. "✋ 💧 💧 ✋ 👎✋👎📬 ❄ 📪 ✋ 💧 💧 ❄ ✋💧 💣✌😐 💧 👎 ✌ '✞ ✋👎' 📬" _{I suppose I did. Though, I suppose this makes our deal 'void' now.}_ Gaster said with a little chuckle, leading to a noise almost like a cross between a screech and a hiss to come from the soul. " **Did you just–?!** " Chara's protests were cut off by the hiss of the lid to the canister opening. " **… What are you doing?** " She asked as her stolen soul floated out.

Gaster gave her an almost warm smile. Fatherly, in a way. "❄ ✌ 💧 ✡ ✋ 💧❄ ✈ 💧❄✋ ✡ 💧📪 ✋ 👎✋👎 💧❄ 📬 📪 ❄ 💣✌😐 ✌ ❄ 💧✋💣✋ ✌ ✋❄✡📬📬📬" _{To answer your first question: Yes, I did just pun. Now, to make another similarity…}_ Before Chara could react, a blaster had materialized before the soul, immediately firing on it. The soul cracked, fractured, then outright shattered. " ❄ 👎 😐 👎 📬" _{Get dunked on.}_ Gaster finished, placing the canister back in its hidden position and simply waiting in the center of the hall now, the bone barriers retracted.

Moments later, Laura showed up, this time looking just a bit nervous. "… Doctor Gaster? Something… Something doesn't feel right about this…" She said slowly, approaching the skeleton hesitantly. "✌ 📬📬📬 ✡ 💧📪 ✋ 💧 💧 ✋❄ 👎 '❄" _{Ah… yes, I suppose it wouldn't}_ Gaster started, mind racing. She didn't remember. "❄ ✌💧📬📬📬 ✌ ✋ 👍✋👎 ❄ ✌💧❄ ❄✋💣 📬 ✌ 💧 ❄ ✌💧 👍 👎📬 👍 💣 📪 ✈ ✋👍😐 ✡📬 ✋ 👍✌ 💧 ✡ ❄ ✌✞ ✋👎 💣✌😐✋ ❄ 💧✌💣 💣✋💧❄✌😐 📬" _{There was… An incident last time. A reset was forced. Come, quickly. I can show you how to avoid making the same mistake.}_ He said, holding his holed hand out to her.

Laura hesitated again, but slowly reached out for it. Moments before their hands met, Gaster's eyelights extinguished. That was her cue to leap backwards, narrowly avoiding impalement on a bed of bones that had sprung up where she had been standing only a second earlier. " ✌❄ ✌ 💧 ✌💣 📬 👍 👎 ✌✞ 💣✌👎 ✋❄ 💧 💧✋💣 📬" _{What a shame. We could have made it so simple.}_ Gaster said quietly as the human pulled her phone out, sending a text. She had just barely sent it when the laser vaporized her.

The gaster blaster vanished moments after, that twisted pink soul now fully exposed, with tendrils branching off of it like some sort of parasite. The scientist grimaced, quickly capturing it in the soul canister, with his magical hands doing the work. A precaution, lest it try to infect him more directly. That was the hard part out of the way. Gaster, as he tried to do at most times, had a plan. Simply killing Laura and leaving was out of the question, as she could just reset. Even if recent events had cast doubt over that, he couldn't take the chance.

The solution was simple, yet also quite a bit… convoluted. He simply had to reach his old lab, power up the DT extractor, and–

The sound of magic gathering was the cue for Gaster to raise the canister up out of the way as the laser tore through him, sawing off a mere fraction of his astronomical HP. "📬📬📬 💧✌ 💧📬" _{… Sans.}_ Gaster said simply, turning around. immediately, he wished he hadn't The pink had nearly fully covered the short skeleton's soul, even forcing his eye into a permanent, pink magical flare. The virus was in full, primal survival mode, and had reached out to the most capable of the 'cast.' Those that had defeated him last time, presumably.

Frankly, it terrified Gaster. So he did the only rational thing

He turned and ran for his life. 

* * *

_This is going… less than well._ Gaster thought as he ducked another fireball, pitched from the furious Toriel, who he had dashed past in the mad scramble to get away from Sans. Honestly, if he hadn't seen the pink strangling her soul, he would've assumed she was doing this out of maternal rage. At this point, he even shifted the canister to be held under his arm, so he didn't have to keep up the magic from holding it up. Fortunately enough, the lanky scientist was able to outpace the pair of borderline possessed monsters, losing them in the winding, maze-like corridors of the CORE. Despite everything, he managed to crack a smile. _I know these halls like the back of my… Never mind._

Gaster looked over his shoulder, making sure he wasn't pursued for no less than the fifth time, when he ran into something. Or rather, someone. Someone in a large, bulky suit of armor.

"Hey! Watch where you're going!" A brash, if subtly feminine voice shouted. "Wait, who are you?" And Gaster looked up from his position on the ground to be greeted with the armored form of Undyne. He did not need this right now. "👍✌ ❄✌✋ 👎✡ 📪 ✋❄ ✌ 👎 💧 👍❄📪 ❄ ❄ 💣✡ ✌✡📬" _{Captain Undyne, with all due respect, get out of my way.}_ Gaster said, standing up again and shifting his grip on the canister.

All this did was earn him a confused look from Undyne. "… What? Wait a minute…" She said, eye trailing down to the soul in the canister. A soul that radiated with her own, forcing it to pulse pink. "Hey! What the hell are you doing with the punk's soul?!" She shouted, a magic spear materializing in her hand.

Before Gaster could react, the furious fish had swiped at him, his soul flickering to green and leaving him trapped. A moment later, spearheads assaulted him on all sides. "Take this, you bastard!" She shouted, only for her barrage to be either blocked by a casually summoned bone, or just outright ignored, the minimal damage to his massive HP pool once again making the doctor seem invincible.

Of course, a silly little detail like her opponent being seemingly invulnerable would never discourage Undyne. She swiped at him, dispelling the magic that bound him in a defensive position, and immediately rushed him down with stabs and swipes. The scientist blocked or dodged them all, slow compared to his last battle, before getting some distance. He couldn't afford to waste any more time here. His magic eyes flared up as he forced blue magic over the warrior's soul. Then he flipped gravity, slamming her into the ceiling. Before she could recover, she came back down. With a flick of his wrist, she was in the air again, before he flung his arm behind him, the rapid gravity switch forcing her to fly back with it.

At hearing a crash behind him, Gaster looked over his shoulder to see that he had just pitched the Captain of the Royal Guard into the Queen of Monsters. "💧 ✡✏" _{Sorry!}_ He called out immediately, before bolting away again.

He had to reach his lab. 

* * *

There were, fortunately, no complications from Alphys regarding reaching the True Lab once he made it back, descending quickly, and hopeful he wouldn't be followed. He stepped out of the elevator confidently, walking undisturbed through the dark hallways, the amalgamates not brought forth to save the corrupt soul he carried, a fact the skeleton considered quite odd.

But, he brushed it off, focusing on the task at hand. He placed the canister within the mandibles of the skull-like DT Extractor, and walked up to the panel beside it. Powering it on. Electricity hummed through the room, red energy being slowly sucked from the soul and into the machine at full force. Gaster smiled wide, this was actually working

And then, a trio of bones stabbed into the machine, forcibly powering it down through virtue of ruining it.

"💧✌ 💧📪 ✌💧 ✏ ❄ ✋💧 ✋💧📫📫" _{Sans, please! This is–}_ Gaster started, only for a much different voice than what he expected to respond.

" ✌❄ 👎 ✡ ❄ ✋ 😐 ✡ ' 👎 ✋ ✍" _[What do you think you're doing?]_


	9. TRUE LAB

_**A/N: Wingdings redacted for ease of reading.**_

Gaster was greeted with an awful sight as he spun around, eyelights pinpricks in his sockets. "{Impossible…}" He mumbled, staggering back, gripping the railing keeping him from tumbling into the lowered pit the extractor was suspended over for support.

Standing in front of Gaster, as best that could be described as standing, was himself. Specifically, the Gaster from the timeline the reformed Gaster was currently in. The melted scientist had the black coat the intact Gaster had melted down over his body, covering it all except for a bit of his white turtleneck showing and his hands. Those hands retained their holes, even while being partially melted. His right eye socket was drooping down, nearly shut, and his left socket was dark with no eyelight to be scene. To a Gaster who had recovered from that, the sight was doubly nightmarish. He knew how that felt. But the most horrific part of looking at his nearly fallen down self was the soul. A glitching, corrupted pink. He was infected.

"[You should know that this was very possible. After all, you… I already did it.]" The infected Gaster said, voice glitching like a record skipping. "[But that isn't the point, the point is that you shouldn't be here.]" He nodded, a dangerous edge coming into his voice. The immune Gaster steeled himself, standing tall once more. "{She shouldn't be here, either, Gaster. You know that.}" It certainly felt odd to be addressing himself.

The melted scientist had to look up to meet his whole self's gaze. "[She is helping this world. Far more than that genocidal maniac.]" He asserted, oozing closer towards the captured, viral soul. Gaster strode in front of him, standing tall to prevent his melted self from reaching it, clearly enjoying the use of individual legs a good bit more, now. "{She is twisting the timelines! You had to have seen it yourself. She's infecting the other timelines and burning them out entirely!}" The intact scientist shouted, referring to the pink husks of the timelines he'd seen from his room, and that the other Gaster had seen as well.

"[That's irrelevant,]" was the response received, the nearly formless scientist almost single-mindedly focused on Laura's soul. The other skeleton gaped. "{Irrelevant?! Well, how about the fact that she's infected damn near everyone in this timeline and forced them into devoting their whole beings to her?}" Gaster said, taking a step forwards, his eyelights extinguished.

With his own hollow sockets, the other Gaster responded. "[That doesn't matter.]"

The intact skeleton was at his wits end, trapped in a world where only he saw the threat. "{Well what does matter then!?}" He shouted, tossing his arms up into the air. The answer he received nearly made the skeleton back off.

"[Sans and Papyrus are safe.]" The infected skeleton said simply. "[They are safe and there are no resets tormenting us. There is nothing wrong here. Stand aside.]" He said, empty socket practically boring a hole through his counterpart's skull. Said counterpart staggered, before standing firm. "{No. Be that as it may, Doctor,}" It still felt odd to be speaking to himself. "{Every other timeline is in grave danger. And that's not even saying what will happen if she completes this 'run!' I will not let this continue. I'm sorry.}"

For a moment, the melted Gaster seemed to hesitate, to pause in thought, then the pink in his soul glitched out and surged again. "[She will not complete a run because she has no care for leaving the underground. I will not say it again, Gaster. Move.]" He said, distorted magic collecting around him. "[I, for one, am not afraid of dusting myself to preserve this peace.]"

The intact Gaster was running out of options. The DT Extractor was broken, and he could feel that her soul still had enough to stick to this timeline like a tick. However, he did have another option. _The robot!_ He thought, the idea breaking into his mind at around the same time a partially melted blaster formed over his infected self's head. "{… I refuse.}" He said quickly, before reaching back to grab and unfasten the canister from the extractor. Then, Gaster did something his fear had made him forget he could do earlier. He teleported just as the blast incinerated half the extractor.

* * *

The robot was designed to run off of Determination for three reasons. The first being that Chara's stolen soul had an ample supply. The second because it was much more efficient than batteries. And the third was to deprive Chara's soul of enough Determination to prevent her from simply resetting. That last part was what the scientist was banking on when he materialized into the golden hallway again, canister in hand.

Gaster pulled out the robot from its hiding place, and jammed the canister inside it. A moment later, it powered on, leaving Laura in this new body, very confused and uncoordinated. "D-Doctor… Gaster…?" She asked weakly, stumbling back away from him and falling on her rear with a clank. Gaster's face was grim. "{Don't bother. That was designed to drain out more Determination than you have. This is over.}"

No sooner were the words out of his mouth did his counterpart appear, albeit in a much less stable warp than he did, between him and the robot girl. "Gaster… Please, no…" She said, reaching out, before falling silent. "[I will not allow this to happen. You will be stopped.]" The melted scientist said, bringing about his magic.

Gaster prepared to defend himself, when an odd red light behind his alternate self made him hesitate. Gears and mechanisms sounded, followed by a cruel voice that froze both the skeletons stiff.

" **Silly old man.** "

 **99999999999**


	10. DETERMINATION

Laura groaned, holding her head as she woke up. "Ow…" She whimpered softly, feeling a dull ache all throughout her body, and a sheer emptiness in her very soul. The last thing she remembered was Gaster standing in front of her, and…

Her eyes shot open as the memories flooded back. Gaster had called her to the last corridor, then he just _killed_ her. Then she woke up. Something wasn't right with that one, she'd have to find a way to update that information. Then another, melted Gaster appeared and stood between her and the whole Gaster and then… Nothing. She could fill that in later, because she had more pressing things to worry about.

Like the pitch black nothingness that she was somehow sitting in, as if there was solid ground under her. "Hello?" She called out hesitantly. Not even that voice in the back of her head, whoever it was, would answer her. There was nothing.

She was alone.

Despite that, she couldn't just lie there. She forced herself up, despite the bone-deep ache that pervaded her entire body. She tried calling out her soul, to possibly provide some light, but the light of her usually star-like pink soul was dim. It was deprived of something. Now, she wasn't a scientist, and the very word made her shudder right now, but she could tell something was wrong here.

"Hello?" She tried again, louder this time. When no response came, she started to walk into the darkness. There had to be something here, she could feel it. Though, it was certainly disorienting, the unchanging environment could easily lead one to believe they were simply walking in place, or on a treadmill of some sort. Eventually, however, she saw something in the far distance.

 **A faint, red glow.**

Given that literally everything else she had seen that wasn't her was blank, unending darkness, Laura was fairly eager to reach it. The woman broke into a run, keeping her soul in front of her for what little light it provided.

It took ages, but she finally reached it, panting and generally out of breath. What she found was certainly an odd sight however. One that filled her with an inexplicable, intense dread.

A little girl in a green and yellow striped sweater was sitting on the ground, cradling a single, floating, red shard that glowed brightly as if her very life depended on it. It was almost like she was trying to prevent a candle from being extinguished.

Despite her fear, Laura had to know why this little girl was here, in the dark, alone. _Just like you._ Her mind reminded her. "H-hello? Little girl…?" She asked quietly, leaning in just a touch closer. Slowly, the girl turned to look at her, showing rosy cheeks, and big brown eyes. "You… You made it here?" She asked softly, in an almost scared voice. Though her mouth never moved.

"Made it here? What do you mean?" Laura asked back, sitting down. She was getting less scared of the girl as time went on. That little girl coughed weakly, before offering a little smile. "Um… Doctor Gaster called me here. Th-the good one!" She added on hastily, at seeing Laura's fear. "What do you mean the good one?" Laura questioned this odd girl, now a bit suspicious.

"Well, the melty one. The other one's a little… Crazy." She said, looking off to the side. "B-but that's why I'm here! Gaster called me in to help, um, fortify your soul against him. S-sorry I'm late…" She said, hanging her head. All throughout her explanation, her mouth only changed with her expression, never opening once.

Laura was conflicted, to say the least. On one hand, this girl terrified her on an existential level for seemingly no reason. On the other, this was an apparently scared, sad girl who was supposedly sent to help her by the good doctor. So, Laura decided to trust her, leaning over and lightly patting the girl's back. "It's… It's alright I mean, you're here now, right?" This earned her a nod from the distraught little girl. "Right. So… We can still do that thing now, can't we?"

That got the little girl to perk up, looking up at Laura. "You mean it? It's a little… weird." She said slowly, looking down at the shard, floating inches over her cupped hands. Laura shifted a bit in her seat. "Hey now, can't be any weirder than what I went through!" She said with a bit of a bitter laugh, but stopped as she saw the girl wince. "Uh, well, let's just do it, yeah?"

That girl nodded, slowly holding out the bloody red fragment. "Your soul is, um, lacking in Determination, but if you put in this piece of mine…" She trailed off, the meaning conveyed with just those few words. Laura swallowed hard, shakily offering her own soul out. Slowly, carefully, the girl pushed the fragment of a soul in, until it fully fused with Laura's soul.

Immediately life, energy, and power all rushed through her; but with them, came sights and sounds. Memories. Screams of agony and obviously unheeded begs for mercy filled her ears. What she saw somehow managed to be worse. Dust. _Monster_ dust. Monster dust _everywhere_. She nearly vomited for it all. It only changed near the end. There were bones, blasts, the gleam of metal, a horrible, nightmarish laugh ringing through her ears.

But, naturally, the worse was the last. A face, much like the little girl's, but twisted and deformed, the eyes pitch black, and leaking some sort of black sludge. The same goo was drooling out of her laughing mouth as she stalked towards her.

She staggered to her feet, eyes wide as the rush ended. "Wh-whoa… That… I mean, I feel better, but… _That_ …" She mumbled, swallowing. Her mouth suddenly felt very dry. "You feel stronger though, right?" The girl asked, suddenly on her feet and looking up at her. Her closed mouth was in an odd, resting smile. That made Laura jump, but feeling her soul, which now had red lines coursing through it, it felt good. Strong. She nodded, giving a tiny smile back. "Uh, yeah, actually! Thanks!" She said, before lightly rubbing the back of her neck. "This is kinda awkward, I don't even know who you are. Um, I'm Laura." She said, smiling a bit nervously.

The child giggled, the sound sending a shiver down Laura's spine. "You know who I am silly, think about it." She said simply, hands behind her back. Laura hesitated, reaching into her mind. Then her blood ran cold and she whispered that name.

"Chara…"

Abruptly, Chara's eyes switched from their warm brown to a bloody red. " **Correct. Greetings, Laura. I've been waiting for this moment for a long time.** " She said, her grin much darker than it had been before. Laura's soul shivered, before floating over into the Fallen's waiting hand, depriving the girl of all that energy, that LOVE that she had felt. " **Much better. This belongs with me. And now… Now I can hear** _ **Them**_ **in this world as well.** " Chara said with an unnervingly giddy laugh.

"Th-them…?" Laura asked quietly from where she had collapsed in the darkness. Though, she quickly regretted asking, from the murderous glare Chara shot her. " **Yes, Them. The Player. The one who has been guiding you, or was supposed to guide you on this journey! They taught me everything.** " She smiled wide. " **I cannot see Them, here, but that doesn't matter. I can hear Them. That's all that matters.** " She shook a little bit from excitement, her smile huge. " **Not just Them. Every single one out there! Every alternate version! They're scared. They're confused. I can understand that. But above all else, They want** _ **more.**_ " She giggled again, the sound not unlike scraping ice. " **They always have and always will. So I will give Them more. I will show Them…** " She whirled around to face Laura, mouth hanging open in a monstrous smile, eyes black. That sludge, condensed Hatred, dripped down to the shadowy 'floor'

" _ **.**_ "

Laura was frantically backpedaling now, pushing herself back with her hands and feet to get away from the demon before her, tears of fear running down her face.

" **YOU.** " Chara intoned, shutting her eyes and mouth once more. When she opened her eyes, they were pitch black, with bright red, four-point stars serving as her pupils. The tear stains of black were still on her cheeks, but she wiped away what was on her chin. Those demonic eyes were focused solely on Laura, and were brimming with contempt and disgust. " **You were meant to be Their** _ **avatar!**_ **A version of Themselves inserted into this story! Their** _ **perfect self!**_ " She roared, steadily advancing on Laura, who was still trying to get away. Dark, tainted Determination swirled into place around Chara's left hand, steadily forming together until it completed a pulsating weapon. Chara's weapon. The Real Knife.

" **But instead, you couldn't hear Them. Instead, you left Them to watch as you did everything** _ **wrong**_ **. You had all that power, all that potential, and you did** _ **NOTHING**_ **with it!** " The megalomaniac snarled, raising the red blade up high with every intent to finish what she started before Gaster had reloaded his save. " **They are my partner. As was Frisk. Frisk changed her mind, but They stayed by my side. You are** _ **worthless**_ **. To me, and to Them.** " Chara said softly, but no less powerfully,

As the genocidal girl panted softly from her outburst, two, familiar buttons materialized before her, presenting her with a choice to make about Laura. Laura, who she viewed as an utter disgrace.

 **[*FIGHT]** **[** ***MERCY]**

The Fallen Child growled. Before Laura could see what choice she had made, the darkness around them abruptly flashed to a nightmarish red, Chara lunging at her almost too fast for her eyes to follow. the older woman screamed as she was grabbed, before being silenced by the unholy blade at her throat.

The mercy button glowed green behind Chara.

"… **That being said, you are still Their creation. Them in a sense. So, I'll spare you. This time. I will show you the right path. The one They guided me on so that my Level Of ViolencE reached its peak. Watch through your own eyes as I demonstrate.** " She said with a twisted, psychotic grin, to Laura's horror.

Then, the world around them started to fade to white with an almost deafening hum.


	11. THE BARRIER

_**A/N: So, so sorry for the delay. A lovely combination of life and wanting to re-edit all the old chapters slowed me down, immensely, and right before the end, too. But with all that out of the way, and a story that hopefully flows better, there are two chapters left. Let's wrap this up.**_

* * *

The melted scientist looked down at the horizontal slash running through him as it glowed red. He only managed to murmur one last, confused " ✌❄📬📬📬✍" _[What…?]_ before dissolving entirely. This just left the mechanical girl that had been standing behind him, eyes a horrifyingly familiar red.

"✋💣 💧💧✋👌 📬 ✋ 😐✋ 👎 ✡ ✏" _{Impossible. I killed you!}_ Gaster said, staggering backwards, eyelights back on, and shrunk to pinpricks. " **Mister Comedian killed me, too. Over and over.** " She said, eyes now actively glowing. " **But you knew that already, didn't you?** " The tendrils of that corrupted, viral soul had seeped out of its mechanical casing, now laced with red veins of pure Determination, and were wrapping around the kitchen knife Chara had picked up from where it had fallen out of her grip in Laura's scramble away from Gaster. Before the scientist's very eye sockets, the knife started to transform and outright mutate, growing a nauseating red as it morphed into the Real Knife, with the twisted little girl experimentally swinging it back and forth. " **Much better. Now then…** " She looked back up at Gaster with that sickening smile, a shudder running down his spine. " **I don't like it when my partners try to stab me in the back,** _ **Doctor Gaster.**_ "

Before either of them could make a move, the air between them fluctuated, with two other skeletons showing up, one stumbling a bit. "SANS, WHY DO YOUR SHORTCUTS HAVE TO BE SO DISORIENTING? AND WHY ARE WE HERE?" Papyrus said, regaining his bearings slowly. "heh, sorry bro, but my skull's been pounding all day, like something's been in it." Sans replied, looking up at Gaster. "and i remember seeing some very bad things happening here, that's why."

"💧✌ 💧📪 ✋📫📫" _{Sans, I–}_ Before Gaster could finish, a pair of those viral tendrils harshly stabbed through both brothers' rib cages. Through their very souls. However, rather than outright killing them, their souls were fully corrupted pink, forcing their magic irises to flare with that same color. " **And what better punishment for a traitor than to be killed with his own progeny?** " Chara's voice came from behind them, followed by an outright demented giggle as the skeleton brothers readied bones and blasters.

Gaster, on the other hand, was not about to fight his sons. Not again. A wave of his hand with magic powering up, forced Sans and Papyrus's souls to turn gray with Cunning magic, inverting their movement, and their attacks, rendering them harmless to the scientist, at least for now. With that out of the way, he readied blasters of his own to bear down on Chara. Blasters which she effortlessly avoided with a graceful twirl that ended with a harsh diagonal slash across Sans's chest. " **Useless, the both of you.** " She growled as the light faded from Sans's eye socket.

In the same motion of the first slash, she decapitated Papyrus, before coming to a stop facing Gaster. An idle glance at the two she now stood between, and had just mutilated, made her chuckle. " **Old habits die hard, I suppose.** "

Gaster, who had been standing by in shock and horror, decided that now would be a good time to run, again. Especially when those soul tentacles were bearing down on him. He had just about made it to the throne room when he heard a loud crack, followed by something rolling past him. On closer inspection, Gaster was mortified to see that it was Papyrus's skull, with cracks along one side, as if it had been kicked. His magic eye had stopped glowing, leaving him back to his original state. "D-DADDY?" He said, actually quietly for him, before he finished dusting.

The wicked laugh and swish of those tendrils cutting through the air alerted Gaster to the fact that he was, in fact, still being pursued; so he ran into the throne room, past a very confused Asgore, and into the barrier room, where he collapsed onto his kneecaps. He had run out of places to run, and had nowhere to hide from the demon approaching. Seeing Sans and Papyrus killed… It was so much different when it was just an image of another timeline, and Gaster could comfort himself with that distance, but this was so much more real. So much closer. Once more, the skeleton felt like retching. This was it. he was going to die, _again_. He had no doubts that this would be permanent, as Chara embodied Determination and certainly controlled the power of saving. There was nothing he could do now but to just sit on the floor and wait for death.

… _The floor!_ He thought, using his magic hands to force the hidden soul canisters up into view. "✋ 😐 ✡ 💧✋✠ 💣✌✡ ❄ ✌✞ ❄ ✋ 💧❄ ✋ ✋ 💣 📬" _{I know you six may not have the highest opinion of me.}_ He started urgently, knowing full well that appeals to the six souls could still reach them. He had watched that nightmare of a fight many times. "👌 ❄ ❄ ✋💧 ✋💧 ❄📬 ❄ ✋💧 ✋💧 👌 ✡ 👎 💣 📪 👌 ✡ 👎 ✡ 📬 💧 ✌💧 📪 ✋ 👎 ✡ ✏" {But this is urgent. This is beyond me, beyond you. So please, I need your help!}

 *** ✌💧❄ called for help…**

* * *

"That was… odd." Asgore said slowly, picking up his watering can from where he had dropped it when the skeleton had bumped into him. Then, he heard footsteps behind him, turning around. "Ah, howdy! How can I–"

He never got a chance to finish, the knife carving through his armor, his body, his very soul in one clean swing. "Why… You…" The fallen king dropped to one knee, only to be, once more, felled by friendliness pellets. "Wow Chara! I thought you were gone for good this time!" That high-pitched voice sounded once more as a buttercup with a face sprouted out of the ground to smile warmly up at the machine. "I mean, both those trashbags blasted you away! But I knew you'd come back, you always do!" He added on hastily, smile growing nervous.

" **You know, Azzy…** " Chara started to advance on the flower, grip on her knife tight. "Chara…?" Flowey said hesitantly, growing worried. " **I don't remember you ever trying to** _ **stop**_ **either of them when they** _ **vaporized me**_ **.** " She said slowly, knife slowly raising up as Flowey recoiled. "B-b-but Chara, it's me! Y-your best friend!" He said, shivering in an emotion he hadn't felt for a long time. In this timeline, at least.

Chara hesitated, knife held high like the blade of a guillotine. She looked reserved, even after her statement, until something prompted her forward. She swung the blade down, again and again. She chopped Flowey into mulch, then kept slashing and stabbing, growing more and more vicious, until there was nothing left.

She took a moment, before rising up and dusting herself off, chuckling at the powder that left her. After all, there was still a job to do. The old man had to die. And so, Chara marched into the barrier room.

She found Gaster knelt down, with the soul containers in the ground, as if he was accepting his defeat.

"Hello, abomination." He greeted her, without his characteristic wingdings. " **Oh, so you can talk again, can you, old man? Perhaps your last words will be coherent, then.** " She said, giggling to herself as the skeleton stood, and turned to face her. His eye sockets were shut.

" **Afraid to look death in the eye?** " The mechanical demon asked, still lightly laughing. " **I suppose can't blame you. After all, you are the last obstacle to completing my run. The 'final boss,' so to speak.** " She raised her knife, then stopped, narrowing her eyes. " **Something isn't right here.** "

"It took you long enough, demon." Gaster said, opening his eye sockets. The magic irises were active, and glowing every color of the rainbow. Suddenly, Chara understood. " _ **NO!**_ " She roared, suddenly charging the scientist. " **You couldn't have!** "

Before she reached him, a blast of light erupted from the good doctor, blinding her and throwing her back. When she both recovered, and could see again, she found Gaster standing tall, with his hands behind his back. The difference being that now he had six huge, skeletal hands behind him, three right, three left. The holes in the palms were filled with each soul's respective color.

"I believe my time in this timeline is coming to an end, Chara. but I'm sure that before I go, I have time for one last experiment…" He said, trailing off. The world around them had changed as well, with them now standing in a grayscale version of the judgement hall. Behind Gaster was the barrier, in all its might. Behind Chara was the lone gray door that was often the only real feature in Gaster's room. Outside the windows was pure blackness with the infinite timelines streaking across it.

As Chara looked around, confused, Gaster took a moment to admire the closer timelines, all showing moments from within the last corridor.

In one, he saw what appeared to be Chara in a hoodie, locked in a duel with Frisk. All of the former's wicked slashes and brutal stabs were literally danced away from by the latter, before Frisk returned fire with rapid kicks from her pink boots. It looked as if they were both getting tired.

In another, he saw Toriel, dressed up almost like Sans, and even the same height. She was coldly judging a shivering, but slightly dusty Frisk. The scene was somber, but not violent as the last one. Toriel seemed to be asking the human a question.

The third, and last, Gaster looked at contained a surprise. In it, Gaster saw himself, shocked, as what he assumed to be a save file loaded into a training dummy failed to produce an actual fighter, but instead gave a pacifist. That Gaster looked up incredulously at Frisk, who looked quite nervous, but accepting.

Finally, Gaster had to tear his gaze away from the lights of the timelines to focus on his opponent, who was trying to glare another hole through him. " **Do you think this changes anything, old man? I'll still kill you, and there's nothing you can do about it.** " She growled, leveling her knife at him.

"That is where you're wrong, Chara." Gaster said coolly, actually starting to smile. "While you may claim to be an embodiment of Determination, we're evenly matched in that regard, at the moment, whatever you might think." He said, making the Fallen actually hiss. "You may have all your power, but I, on the other _hand_ , have the strongest weapons in the world. You know you cannot stand before me. So…" Gaster smirked wider.

"Let's begin, shall we?" The empowered scientist said, raising an arm forwards. The aqua hand rose with it, before firing a beam out of the power well in its palm. Chara, however, had seen enough magic attacks to know when to stand still for a blue one. "Hm. You know the rules well, hellspawn." Gaster said, still grinning.

"But that's just it, isn't it? You have to play by the rules. I, on the other _hand_ …" He said, snickering a bit as the orange hand fired a beam as well, the magic intersecting over Chara's mechanical body. No way to avoid damage anymore. Soon enough, she had to jump away to prevent her health from being drained any further. " **You already used that one!** " She snarled,twisted knife at the ready.

A sharp noise, and she found gravity's influence invert, sending her hurtling towards the ceiling of the arena, and towards a bed of bones that awaited her. No sooner did the demonic child land with a metallic crunch than did a quartet of blasters fire on her, followed by her being slammed back onto the floor. A moment later, yet more attack bones sprung up under her, piercing her robotic body and propping it up.

"So, this is your end, demon? Effortlessly defeated by the one person you never expected? The one you didn't have any practice with? Just because he has a few shiny new tools to use?" A dark, vindictive chuckle escaped Gaster as he slowly walked towards the girl's limp, artificial body, the tendrils of soul energy having retracted into it. A wave of his arm sent the soul-powered hands back. He didn't need them to just finish her off. He would do it with his own power. They had served their purpose. "A shame. I was hoping to gauge your abilities more thoroughly. Perhaps intervene on Sans' behalf if I can gain the energy for it." he mused, the clicking of his shoes stopping just before the Fallen, blasters materializing in a ring around her. "Oh well, one should expect poor results from an impulsive study, after all." Gaster said simply, then willed his weapons to fire.

" _ **NO.**_ "

The scientist then had to duck to avoid the ring of blood red energy that was fired off from Chara's fused soul, cleanly bisecting his blasters. Black sludge was starting to leak from her broken body.

" _ **THIS WILL NOT END NOW.**_ "

That mechanical body of hers started to move again, lifting itself off of his bones. Her right arm, however, was too badly damaged to respond when she willed it to move. So she tore it off.. That didn't slow her in the slightest. SHe was left handed after all.

" _ **I REFUSE!**_ "

A burst of red light bowled the good doctor over, sending him sprawling. Gaster was left on his hands and kneecaps, his massive hands still floating behind him, but needing a bit of reorienting. Of course, when Gaster turned his eye sockets to where Chara had been, what he saw was not pleasant.

The robot's formerly placid expression was replaced with an outright hellish smile of twisted metal, drooling condensed Hatred. The LEDs of her eyes had been blown out, yet two twinkling points of red light gleamed in the sockets, even past the sludge dripping down over her cheeks. Her severed arm had been replaced by a mass of pink, black and red tentacles, all writhing and squirming as if independent, but forced into line by another power. Where metal had been blasted away there now shone pale, twisted flesh in its place, pulsing to the heartbeat of the now exposed soul in her chest. A soul that had a half-metal, half-organic container.

For the first time in his memory, Gaster had to check his opponent.

 ***CHARABOMINATION**

The skeleton swallowed. The number of nines beside her attack stat was disconcerting at best.

" _ **So, DoCtOr GaStEr. I bElIvE yOu WaNtEd A lOnGeR fIgHt?**_ " The creature before him spoke, its voice nearly as twisted as his own had been, if not worse in some regards.

" _ **LeT's BeGiN. AGAIN!**_ " The Fallen roared, soul tendrils that had replaced her arm lashing out like whips. Gaster was forced to teleport in short bursts to avoid the coiling, cracking tentacles. Unfortunately as soon as he had dodged those, a series of red slashes was thrown his way, courtesy of the abomination madly slashing at the air in front of her. This time, simple teleporting wasn't enough, Gaster having to summon up attacks of his own to slow and stop the flurry of strikes. Though eventually, the burst from one of his bone walls shattering sent him flying backwards, having to be caught by the green hand. " _ **wHaT's ThE mAtTeR? rAn OuT oF sTeAm?**_ " The creature taunted, a sadistic, distorted laugh echoing out after it as the Charabomination started to approach. " _ **Hm… I wOnDeR hOw MuCh EXP YoU'rE wOrTh…**_ "

Gaster shut his eye sockets. That one hit, even though it was through his bones, was enough to put his colossal health pool in the red. It was over, and he'd let something like this happen. Something like _that_ exist. This didn't make any sense! He had the best weapons that existed, he was a monster that had six human souls! He was nearly a god! Why was he losing?! How strong was this creature to do this? Did he even stand a chance?

 _Doctor, please don't give up._

Gaster's eye sockets opened up slowly, looking to where he thought he'd heard that voice. What greeted him was what appeared to be a green silhouette of a young human boy. Warmth filled his bones as the green power well of the hand he was leaning against started to feed him its healing energy.

 _We know you can do it._

A purple child with glasses appeared out of the purple power well, magic strings lifting him into the air and back to his feet.

 _You can't give up now!_

The orange soul spoke next, infusing Gaster's weakened bones with new energy. The Fallen growled, lashing out with her tentacles." _ **WhAt Is ThIs? DiE!**_ "

 _We'll help you!_

The aqua soul placed a barrier of magic energy between the tendrils and Gaster, blocking them from harming the scientist as he was reinvigorated by burning them up as they tried to pass through. Regardless, the Charabomination continued to approach.

 _You just have to let us!_

… Until a ballet shoe connected to a phantom leg of blue soul energy kicked her in the jaw, forcing her to stumble backwards. Gaster looking in awe at the souls around him, ready to help him.

 _We'll beat her!_

A gunshot sounded out, with a yellow beam piercing into the creature, forcing her back even further and drawing a distorted scream. Gaster was standing tall now, a smile on his face, and his rainbow magic irises glowing brighter than ever.

 _TOGETHER!_ "TOGETHER!"

Gaster had cheered it with them, now letting the souls work with him, rather than wielding them as weapons or tools. He threw out his arms, the hands going into action.

The green hand snapped, locking the Charabomination in place by forcing her soul green, followed by a constant beam of aqua energy and purple magic strings winding around her to help keep her still for the others. Fist-shaped, orange projectiles, yellow laser bullets, blue ballet shoes, and Gaster's bones and blasters all slammed into the forcibly immobilized creature, courtesy of the remaining hands, and Gaster himself.

The Charabomination outright snarled, before loosing a massive roar that disrupted the magic holding her in place, before lunging at Gaster in a blind rage, determined only to sink her knife into his very soul. Before she could reach him, though, she was stopped by a beam of blue energy. Then it was joined by orange. Green, purple, aqua, and yellow all joined in, every soul in unison to protect the doctor and defeat the abomination before them.

Gaster, who had flinched back at the rushdown, smiled wide at realizing that these six had saved him yet again. Of course, they couldn't hold back that beast for long, she was already starting to claw her way forwards in the combined beam. Gaster simply smiled, gathering together everything he had, all his Determination, into the maw of one last blaster that he had summoned in front of him, turning the blaster's energy red. Without wasting another moment, the scientist fired, adding his Determination to the attack.

The rainbow beam started to wear away the beast's body, stripping it down and shoving it back. Metal was peeled away, Hatred burned off, soul energy vaporized. All building and forcing her back until with one last cry, the twisted abomination's body crumbled, reduced to ashes. Though, before the beam could shatter the soul, Gaster signaled the souls to cease fire.

Slowly, the demented soul started to rise up, pulsing and trying to latch onto a host, to form a pseudo body, to do anything at all that would allow it to _kill the skeleton._

 _Ping!_

Gravity for it abruptly shifted, flinging it towards the gray door, that one of the hands had opened up in advance. The doorway lead to the destroyed timeline that Chara was native to, which she recognized, as soon as she had the coherence to form that phantom version of her body. " **What are you doing, old man? What will this do? I can still use all this power in a timeline you can't stop me in!** " She said, grinning wide and starting to laugh.

"Oh it is funny, Chara. Because that virus was tailor made for this timeline. An intact one with these parameters. The one you're in is destroyed, with no hope of restoration." Gaster said, with the sort of smug grin one could only have when one is explaining something seemingly obvious they have used to win.

And Chara's face was the perfect picture of a sore loser.

" _ **YOU–**_ "

Chara couldn't finish, as the door was slammed in her face, moments before it ceased to exist.

He had a moment of peace, then, looking back out over the timelines he could see. Chara and Frisk's fight was still raging, magic red knives and lasers being flung by the increasingly desperate Chara at the increasingly wounded Frisk.

Toriel had harshly dismissed Frisk, vanishing with a warp and leaving the girl trembling.

That alternate version of himself had stopped fiddling with the values of the dummy and finally listened to Frisk, slumping a bit.

Gaster smiled, now turning to look at the six hands, the six Souls around him. "Thank you all, for everything. But, we aren't done yet." He said, smile turning into a neutral, determined expression. Almost like what he had seen the human wear oh-so often. He reached out, a yellow, four point star appearing under his own hand. A Save Point. "There are a few things we need to set right."

The world suddenly jumped into razor sharp clarity for just a moment, before fading and blurring away.


	12. SAVE SCREEN

_**A/N: Warning: Dangerously meta**_

* * *

 ****

 **[*CONTINUE]** **[*RESET]**

These were the only features the good doctor could see asides from the patch of grass bathed in sunlight that he stood in. Gaster could feel the presence of the six souls he had absorbed, but they had not manifested like they had when he had fought Chara.

While Gaster needed their power, he needed to do this alone.

This place was one Gaster had seen only a few times The utter apex of the powers of Determination. A place where, if one had the right knowledge and abilities, one could have access to the whole of the timeline. A place that had been the center of Gaster's studies, even if he didn't know it at the time. It was time to see if he knew enough. The scientist reached out a hand, focusing all his will and Determination.

Gaster took hold of a doorknob.

He flung it open right away, his rainbow magic irises burning bright with the power necessary to keep the door open. The skeleton walked inside, and found himself in a cave a way up Mt. Ebott. He found himself standing behind a rather familiar young woman.

It would be so easy, honestly, to just vaporize her here and now. To blow this woman away for sins that she had not yet committed. That, from the sound of it in the judgement hall, she had no intention of committing. And yet…

Gaster sighed, shaking his head. He couldn't do that. He watched her, waiting for that crucial moment when she tipped off balance, and reached out. A magical hand took hold of her bringing her back away from the edge of the pit. " _You should not be here, human. Go back to your home. Stay away from the mountain._ " He said, giving her a light push towards the mouth of the cave. He barely even noticed how odd his own voice sounded.

Laura's eyes went wide as she saw the skeleton, but, terrified, she nodded and ran outside. She had never said a word except for a few startled noises.

 _One down._ Gaster thought to himself, quickly retreating back through the doorway. Best to keep that strain on his magic minimal. _Though, that was the easiest part of this._

He shut the door for a moment, before opening it again, finding himself in a much different locale. Namely a rather drab room in what he was fairly certain was an orphanage.

This was rather confusing, as Gaster had never seen anywhere like this in the timeline, and it was taking quite a bit of power to project himself here. It was only when he looked out the nearest window did he see why that was. Gaster couldn't stop himself from staring. It was the surface. Not the side of the mountain, but the actual _surface._

The scientist practically had his skull pressed to the glass. After so long, he finally saw it firsthand. He almost didn't hear the actual door to the room opening.

"Who are you?"

The gentle voice of a child snapped Doctor Gaster out of his sightseeing, the skeleton turning around to see a small child in a large sweater, a fresh bandage on from a little scrape. A child who, despite having her eyes shut, was still looking directly at him. Frisk.

" _Oh. I did not hear you come in._ " Gaster said, tugging on his collar. His voice was still odd, in the Aster font, but oddly ringing. " _My name is Doctor W.D. Gaster._ " He said with a nod, only for Frisk to look a bit nervous. "A doctor? Were… were you called here for me? It isn't that bad, r-really!" She said with a nod, pointing to the bandage she had already put on.

Gaster couldn't stop himself from chuckling. " _No no, Frisk. That is not why I am here. Tell me, are you really happy, here?_ " He asked gently, watching how she looked around, or at least made the motion of doing so. "Well… It would be nice to, um, have a family…" She said with a little nod, now looking down. "One that's as bright as you!" She added, giving him a small smile.

" _Bright? What do you mean, Frisk?_ " He asked, a bit confused, only for Frisk to giggle. "Doctor Gaster, your whole body, especially your eyes, are glowing with rainbows! Um, at least to me." She nodded, smile getting a bit smaller. " _... You can sense my magic? Interesting. But, that's besides the point. I know where you can find a family that will love you, Frisk._ "

This caused the little girl to perk up immediately. "Really? I can have a family?" She asked, scampering up to the scientist with a wide, eager smile. Gaster nodded with a wide smile on his face. "Yes, child. All you need to do is climb the mountain. Mt. Ebott." He said, taking a fragment of his currently powerful magic and warping it, having it shine bright right over the hole where the eighth child was meant to fall down. " _Now, I know about the legends, and I know you may have some reservations, but-_ "

"I don't care! I'm gonna get a family!" She said with a massive smile, practically bouncing in place as she rushed back towards the door. Gaster could only stare as that little girl's determination showed itself again. She really was unstoppable.

With that taken care of, Gaster stood again, quickly making his way through his own door. That was a massive strain on his magic reserves. He could feel his body destabilizing. Monsters never were suited to time manipulation.

Regardless, he still had one last experiment to perform before he left this timeline. Something he had to know.

"What… What did you do?" A small, nervous voice came from behind Gaster, underneath the large buttons. A little girl stood there, body partially transparent, and looking at him with large, reddish brown eyes. Chara.

Gaster scowled, raising a hand. A blaster appeared before it, charging its beam. Right now, he could remove the other major threat to this timeline and the happy ending. One laser is all it would take, and she'd be gone forever.

However, as he looked upon the cowering girl, a memory from times long past surfaced in his mind.

* * *

It wasn't long after he was appointed as the Royal Scientist when he had received a summons from the king and queen. Now, Doctor Gaster was rather used to these. It seemed that he was invited to tea with the Dreemurrs fairly regularly. Most likely because he knew Asgore rather well.

However, this was not like the regular invitation. This one was more formal, and made no mention of tea. In fact, it emphasized his status as a doctor. And asked that he maintained absolute secrecy.

Now, Gaster did find that odd, but he teleported over to Asgore's home regardless. After all, if it was odd, that just meant that he needed to investigate.

He was not prepared for what he saw when he arrived.

Asgore and Toriel were standing outside, waiting for him. This wasn't too unusual. What was unusual, was what was standing mostly behind the queen. Gaster had initially passed the shape off as just their son, Asriel. It was not Asriel.

Cowering behind the boss monster, was a small human child.

"Doctor Gaster, this is Chara. A human girl who fell into the underground." Asgore said, as Toriel whispered sweet, gentle things to try to coax the child out into the open. The scientist knew this was serious, as Asgor never used his title. "Tori attempted to heal her, and it seems to have worked, but… we aren't sure, given the differences between humans and monsters. We thought that you might be able to-"

"I'll do it."

At first, Chara was rather unresponsive at best, looking at him warily with those big brown eyes of hers. As they met more often, for checkups and other such things, she started to open up to him.

Soon after, he had started to teach her magic, and a bit of botany.

* * *

Gaster blinked as the memory stopped, leaving him back in that place outside of time once more.

Once more the scientist looked down on the cowering girl, ready to cast judgment. This time, however, he sighed, dismissing the blaster.

Gaster walked over to Chara, kneeling down next to her and placing a skeletal hand on her shoulder. "Chara. Look at me. I am not going to hurt you." He said softly, slowly getting the girl to calm down and look back at him, confused. "Though, I must warn you. You saw what happened to the other you, correct?"

When she nodded, he continued. "Please, Chara. Do not become that. Do not kill wantonly. Do not let your LOVE overwhelm you. For your own sake." He said, nodding. "Now go. A little girl named Frisk will be waiting for you on the flowerbed." He said with a soft smile.

Chara gave a hesitant nod, before walking off into the darkness, and subsequently vanishing.

 _Hopefully she'll listen._ Gaster thought, before turning away from the buttons, looking up at where Chara seemed to stare in all those timelines before destroying them. Then he channeled all the power he had into himself, into his eyes.

The rainbow colors swirled and glowed, brighter and brighter, until his magic irises were white. Until he could see it all.

Until he could see _you._

Gaster saw eve _faibgjds_

 _Fesidd_

 _ERR_

AND I GAZED INTO THE VOID. I GAZED UPON ENDLESS TIMELINES STREAKING THROUGH THE BLACKNESS. I GAZED UPON GOOD AND EVIL. RIGHT AND WRONG. AND I SAW PAST THEM. I LOOKED PAST THE VOID AND I FOUND IT.

I SAW WITH EYES THAT WERE NOT MINE COUNTLESS TIMELINES PLAYED OVER AND OVER. I SAW A GAME MADE FOR AMUSEMENT. I SAW STORIES WRITTEN, PICTURES DRAWN TO CONTINUE THE TALE. I SAW THOUSANDS, MILLIONS OF HUMANS WHO COULD NOT COPE WITH IT ENDING. WHO WANTED MORE. I SAW A SMALL, WHITE DOG. IT WAS ALL LAID BARE BEFORE ME, AS I GAZED INTO THE DARKNESS. I KNEW ALL. THE SHADOWS CUT INTO MY MIND AND TOLD ME, CUTTING DEEPER.

DARK  
DARKER  
YET DARKER

 **Enough.**

I see you. All of you reading this. I cannot tell how many you are, as I am viewing this at the time of writing. There may just be the author that sees this, or there may be hundreds of you. I am not sure.

I am speaking in a font that you can read with more ease than my standard Wingdings. I want myself to be understood. It is literally melting down my body to accumulate the power needed to deliver this message. I will be as I was in the void soon. But that is not important.

I must be heard.

Do note that I cannot threaten you. I am currently omniscient in my world, but speaking through a narrow medium in yours. I am near-omnipotent here, and completely powerless there.

All I can do is ask.

Please stop this. Just leave our universe be. That is all I ask. You have the grace to give us a happy ending, if you so choose. Please just leave it at that, that is all I ask. Do not create more hardships for us.

Please.

There, human. That is all I have to say. Please take heed of it. And now, I will wrap up your story.

I nodded into the darkness that you were gazing at me from, and walked back into my gray doorway, gently shutting the door behind me.


	13. GRAY ROOM

_**A/N: Short little wrap up chapter.**_

* * *

Gaster sighed as he looked over the arching timelines on the back wall of his gray room. He had forgotten how dull nonexistence was. All he could do was keep watch over the countless timelines. Observe.

Even after he directly interfered.

He shook his head. He didn't belong there… even if he was now linked to that timeline. He had his own. His own that had completely forgotten him as well.

It was an unpleasant thought.

And yet, he had saved all the timelines from a virus. He'd given advice to that world's Chara. Then he did… something else. Something he couldn't quite remember. Whatever it was, it had to have taken a lot of power to return him to this sorry state. And had used up one of the DT syringes. Thankfully as he was he could not feel the pain of his melted form.

He allowed a bit more of a smile across his face, reaching into what remained of his coat and pulling out the remaining, full syringe of that glowing red liquid. Pure Determination. He took a moment to examine the syringe, looking over it, lightly tapping it, before replacing it in his coat.

He still had his backup plan, all was not lost on that front.

All he had to do now was wait and see if he could find a way back on a more permanent basis. And back into his own timeline.

And perhaps… Keep tabs on that timeline he had gone through.

Make sure it all turned out okay.

* * *

An immeasurable distance away, yet remarkably near, there was a room that was identical to the one that housed the timeline-jumping Gaster, yet held one massive difference.

There was no Gaster.

All that remained was a pinkish stain on the floor. A sign of the infection that had taken him.


End file.
